Research Article Received: 26 May 2014
Revised: 5 February 2015
Accepted article published: 10 February 2015
Published online in Wiley Online Library: 25 February 2015
(wileyonlinelibrary.com) DOI 10.1002/jsfa.7129
Posidonia oceanica banquettes as a substitute for straw in dairy goat rations: metabolic and productive effects Cristina Castillo,a* Angel R Mantecón,b Juan Sotillo,c Cándido Gutiérrez,c Angel Abueloa and Joaquín Hernándeza Abstract BACKGROUND: The marine plant Posidonia oceanica (L.) Delile can be a source of fibre to increase the efficiency of product costs. The aim of the present study was to assess the productive (milk production and performance) and metabolic (blood metabolites) effects of P. oceanica in the ration of dairy goats as a substitute for straw. Posidonia oceanica was used at 225 and 450 g day−1 per goat in lieu of barley straw. RESULT: Supplementation with P. oceanica had no detrimental effects on the body weight, milk production and metabolic status of goats. Goats fed P. oceanica produced more milk fat, had a lower somatic cell count in their milk and showed a decreased risk of oxidative stress. CONCLUSION: Goats can be fed P oceanica at levels of up to 450 g day−1 without detrimental effects on milk production and health, therefore P. oceanica can be a substitute for barley straw in the nutrition of goats. © 2015 Society of Chemical Industry Keywords: goats; Posidonia oceanica; production; metabolism; oxidative stress
INTRODUCTION
602
A major characteristic of goat production in the Mediterranean area is its dependence on pasture land.1 In these semi-arid areas, animal production is increasingly reliant on supplemental feeding. The cost of many traditional feeds restricts their use in many countries, and producers are turning to alternative feed sources.2 One of them, especially in Mediterranean countries, is marine plants. Posidonia oceanica (L) Delile is a seagrass that is widely distributed along Mediterranean coastlines. This marine plant is more complex in evolutionary terms than algae. When leaves of P. oceanica are not functional, they lose their green colour and become brown, whereupon they subsequently break off and are carried to the coast, appearing as ‘banquettes’. Recent studies have demonstrated that these wastes could have an important role in the feed of ruminants as a source of fibre,3 which could help to optimise production costs. The chemical composition of P. oceanica banquettes shows a higher ash content and lignin fraction than cereal straw.4 Additionally, the content of neutral detergent fibre in P. oceanica suggests a potentially positive effect for animals that consume high-grain diets, by promoting salivation and chewing activity. Despite these promising results, to our knowledge, there are no studies concerning the effects (in terms of production and/or animal health) of introducing these banquettes as a component of the ruminant diet. The farming system in the Murcia region of southeast Spain is mainly based on goat husbandry, especially the Murciano-Granadina breed. With an annual yield of 35 million J Sci Food Agric 2016; 96: 602–609
litres (some individuals have reached a mean milk production of about 1.3 kg day−1 over 305 days of lactation), the milk of Murciano-Granadina goats is characterised by a fat content of 5.4 g, a protein content of 3.6 g and a dry extract content of 14.5 g per 100 g and is considered highly suited for the production of different varieties of cheeses.5 Based on our previous results on the chemical composition of P. oceanica,3 the aim of the present study was to assess the effects of introducing P. oceanica as a substitute for straw in the feed of dairy goats on milk production and metabolism (blood metabolites, including oxidative stress).
METHODS Collection of P. oceanica samples In compliance with protection rules (Dir. 92/43/CEE) for areas within the Natura-2000 Network, permission for sampling was
∗
Correspondence to: Cristina Castillo, Departamento de Patología Animal, Facultad de Veterinaria, Universidad de Santiago de Compostela, E-27002 Lugo, Spain. E-mail: [email protected]
a Departamento de Patología Animal, Facultad de Veterinaria, Universidad de Santiago de Compostela, E-27002 Lugo, Spain b Instituto de Ganadería de Montaña, CSIC-ULE, Finca Marzanas, E-24346 Grulleros-León, Spain c Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad de Murcia, Murcia, Spain
www.soci.org
© 2015 Society of Chemical Industry
Posidonia oceanica in dairy goat nutrition
www.soci.org
obtained from the local government. The study was conducted at La Manga beach (37∘ 38′ –37∘ 50′ N, 0∘ 41′ –0∘ 52′ W) located in Murcia (southeast Spain). Samples of banquettes of P. oceanica were collected on the same day directly from the beach, above the water line; these were washed with distilled water and sun dried for 48 h in a warehouse. Subsequently, leaves were supplied to the experimental animals. Animals Twenty-four multiparous Murciano-Granadina non-pregnant dairy goats (4.0 years old, mean weight 42.5 kg) in the late-lactation stage were used for the study. We chose females that were in the late-lactation stage so that neither pregnancy nor milk yield could condition blood parameters. The study was conducted in the Murcian Institute of Investigation and Agricultural Development (IMIDA). During the experiment, each group was kept and fed in a separate pen. All goats were housed in a building with a partially controlled environment (the temperature varied between 16 and 20 ∘ C). Throughout the study, the animals were cared for and managed in accordance with official Spanish guidelines on animal care. Experimental design and animal treatments The study period was from week 16 of lactation (112 days in milk (DIM)) until week 22 (154 DIM), in the declining phase of the lactation curve and 15 days prior to oestrus induction and synchronisation for subsequent artificial insemination. The goats were randomly divided into three equal groups of eight. An individual goat received daily 1.4 kg of concentrate (Cargill Animal Nutrition, Torre Pacheco, Murcia, Spain) (Table 1) and 400 g of alfalfa hay. In addition to concentrate and alfalfa hay, the goats of the control (CTRL) group were offered 450 g of barley straw, which was substituted by 225 and 450 g of P. oceanica in the PO-225 and PO-450 groups of goats respectively. The chemical
contents of P. oceanica, barley straw and alfalfa hay are listed in Table 1. Concentrate and alfalfa hay were offered in the same container simultaneously to each pen in two equal portions at 09:30 and 14:00. Water was available ad libitum. Forage refusals (straw and/or P. oceanica) were collected at 07:30 before the distribution of fresh feed and were subsequently weighed. Concentrate and alfalfa hay refusals were non-existent in the three pens. Individual goats were weighed weekly throughout the trial. All procedures and protocols were approved by the Ethical Committee of the Faculty of Veterinary Medicine (Murcia University). Sampling collection Blood samples were collected by jugular venepuncture (Vacutainer® tubes without EDTA) at 112 DIM, prior to the introduction of P. oceanica into the diet (sampling 1), and every week at 119 (sampling 2), 126 (sampling 3), 133 (sampling 4), 140 (sampling 5), 147 (sampling 6) and 154 (sampling 7) days after milking and prior to feeding, between 08:30 and 09:00. Mean body weight and mean milk production were recorded on the same day, prior to blood sampling. Milk samples were obtained from each goat using sterile vials with preservative (azidiol), and these were refrigerated at 4 ∘ C. Biochemical determinations Blood samples were centrifuged (2000 × g for 20 min) and the serum was immediately frozen (−20 ∘ C) for subsequent analysis. Serum glucose, 𝛽-hydroxybutyrate (BHB), serum urea nitrogen (SUN), creatinine, total serum proteins (TSP), aspartate aminotransferase (AST) and 𝛾-glutamyl transferase (GGT) were measured using standardised diagnostic kits from RAL (RAL Técnica para el Laboratorio SA, Barcelona, Spain). Non-esterified fatty acids (NEFA) were assayed using a kit from Wako Chemicals GmbH (Neuss, Germany). In all cases, appropriate controls were
Table 1. Composition of concentrate and chemical composition of concentrate and feeds Ingredients of concentrate (g kg−1 DM) Wheat bran Soy bean Barley Malt Sunflower oil (30%) Rye Honey bean Corn flour Cane molasses Calcium carbonate Vitamin/mineral premixa
266.5 250 150 80 70 69.9 41.6 36.7 10 14.9 10.4
Chemical composition (g kg−1 DM)
Concentrate
Barley straw
Alfalfa hay
P. oceanica
Crude protein (CP) Neutral detergent fibre (NDF) Acid detergent fibre (ADF) Acid detergent lignin (ADL) Ether extract (EE) Ash Net energy of lactation (Mcal kg−1 )
175.5 366.4 190.8 – 30.9 76.0 1.5
3.7 72 46.4 8.4 1.6 7.2 –
17.0 49.5 24.5 8.0 2.0 11.2 –
4.1 70.4 55.8 11.4 1.4 17.6 –
J Sci Food Agric 2016; 96: 602–609
© 2015 Society of Chemical Industry
wileyonlinelibrary.com/jsfa
603
DM, dry matter. a Premix contained 10 g Ca, 5.7 g P, 3.4 g Mg, 0.72 mg Se, 154 mg Zn, 14 900 IU vitamin A and 3100 IU vitamin D kg−1 DM.
www.soci.org used. Physiological and pathological control sera were analysed alongside the samples for two-point quality control. Serum antioxidant capacity (SAC) was measured as described by Trotti et al.6 using an OXY-Adsorbent test kit (Diacron International, Grosseto, Italy); the results are expressed as μmol HClO mL−1 . Reactive oxygen substances (ROS) were assayed using the standardised spectrophotometric d-ROM test (Diacron International);7 the results are expressed in arbitrary ‘Carratelli units’ (CARR U), with 1 CARR U corresponding to 0.08 mg per 100 mL H2 O2 . The oxidative stress index (OSi) was calculated as ROS/SAC.8
A
C Castillo et al.
The chemical composition of milk (protein, fat, lactose, non-fatty solids (NFS)) was determined using an infrared spectrophotometer (Milko Skan S 50B, Foss Electric, Hillerød, Denmark), and somatic cell counts (SCC) were obtained using a Fossomatic 80 (Foss Electric). The analytical procedures for determining the chemical composition of forage were described previously.9 The ash and N contents of P. oceanica, barley straw and alfalfa hay were analysed following AOAC methods 942.05 and 984.13 respectively.10 Neutral detergent fibre (NDF) was analysed according to the procedure of Van
CTRL
49
PO-225
Live weight (Kilograms)
47
PO-450
45 43 41 39 37 35 1
Milk production (Kilograms)
B
2
3
4
5
6
7
2.5
2
1.5
1 CTRL PO-225
0.5
PO-450 0 1
2
3
4
5
6
7
604
Figure 1. Mean live weight and milk production (± standard error) of goats in non-supplemented (CTRL) and Posidonia oceanica-supplemented (PO-225 and PO-450) groups during study (samplings 1–7). For live weight (A), ANOVA indicated a significant effect of time (T) (P < 0.001) but not of supplementation (TR) (P = 0.833) or T × TR interaction (P = 0.294). For milk production (B), ANOVA indicated significant effects of T (P < 0.001) and T × TR (P = 0.001) but not of TR (P = 0.862).
wileyonlinelibrary.com/jsfa
© 2015 Society of Chemical Industry
J Sci Food Agric 2016; 96: 602–609
Posidonia oceanica in dairy goat nutrition
www.soci.org
Soest.11 Samples were weighed in F57 Ankom filter bags (Ankom Technology Corp., Macedon, NY, USA) and washed at 100 ∘ C for 1 h with neutral detergent in an Ankom fibre analyser (Ankom Technology Corp.). Sodium sulfite and a heat-stable amylase were used in the analysis of NDF, which was expressed inclusive of residual ash. Acid detergent fibre (ADF) and acid detergent lignin (ADL) were determined in the bags containing residual NDF in an Ankom fibre analyser according to AOAC method 973.18.10 Statistical analysis Data were tested for normal distribution using the Shapiro–Wilk test. Serum parameters and live parameters (mean live weight and milk production) were subjected to analysis of variance (ANOVA) with ‘group’ as the fixed main effect and ‘sampling date’ as a repeated measure effect; thus the model considered the effects of treatment (TR), time (T) and the T × TR interaction. SCC were normalised by log10 transformation. Differences in milk composition parameters between groups at the beginning (112 DIM, sampling 1) and end (154 DIM, sampling 7) of the experiment were determined by ANOVA. All statistical analyses were performed using the SPSS 19 package (SPSS Inc., Chicago, IL, USA). Bonferroni corrections were included for post hoc analysis. Significance was defined by P < 0.05 and trends at 0.05 < P < 0.1.
RESULTS Intake and milk production The mean daily intake of forage (straw or P. oceanica, excluding alfalfa hay) was 300 g of barley straw per goat in the CTRL group and 126 g of P. oceanica per goat in the PO-450 group (fed only the marine plant). In the PO-225 group the mean daily intake was 187 g of barley straw and 47 g of P. oceanica per animal. Production parameters such as body weight and milk production are shown in Fig. 1. Supplementation with the marine plant had no significant effect on body weight and milk production. A progressive and significant decrease in milk production was observed during the study.
Goats fed either level of P. oceanica had higher levels of milk fat, and this increase was greater in the PO-225 group (Table 2). Other quality attributes of milk (protein, NFS, lactose and SCC) were not affected by P. oceanica supplementation. Metabolic parameters Antioxidant production was significantly influenced by the time course and also by supplementation with P. oceanica (Fig. 2). Goats fed P. oceanica ended the study with higher SAC than CTRL goats. In addition, animals of the PO-450 group showed higher antioxidant activity than animals of the PO-225 group. Considering OSi ratios, supplemented goats ended the study with lower oxidative stress (OS) risk than CTRL goats, especially animals of the PO-450 group. Figure 3 presents the evolution of the energy-related parameters during the study period. Concentrations of glucose fluctuated without a clear pattern among the three groups, and all goats had similar glucose levels. NEFA concentrations in both PO-225 and PO-450 goats were lower than in CTRL goats. BHB concentrations in the CTRL group increased progressively throughout the experiment, whereas the PO-225 and PO-450 groups maintained higher and more stable BHB levels, except for the last sampling, where CTRL and PO-450 goats had higher BHB concentrations than PO-225 goats. The levels of SUN, creatinine and TSP and the activities of AST and GGT were similar among the three goat groups (Table 3).
DISCUSSION Productive values There were no refusals of concentrate and alfalfa hay by animals in the three pens, so only mean ingestion of the other types of forage was registered. The PO-225 group consumed higher amounts of barley straw than P. oceanica leaves, which could be attributable to a selective effect of the animals against the new feedstuff. In fact, goats of the PO-450 group were those who consumed the least amount of forage. This difference in the amount of ingested
Table 2. Mean values (± standard deviation) of milk components at beginning (sampling 1, 112 DIM) and end (sampling 7, 154 DIM) of study and effects of ANOVA Groupa Item Fat (g per 100 g) Sampling 1 Sampling 7b Protein (g per 100 g) Sampling 1 Sampling 7 NFS (g per 100 g) Sampling 1 Sampling 7 Lactose (g per 100 g) Sampling 1 Sampling 7 SCC (log10 ) Sampling 1 Sampling 7 a b
CTRL
PO-225
PO-450
P value
4.6 ± 0.2 4.7 ± 0.7a
5.3 ± 1.2 6.1 ± 0.9b
5.2 ± 0.8 5.9 ± 0.8b
0.309 0.006
3.8 ± 0.1 3.8 ± 0.1
4.3 ± 0.2 4.2 ± 0.9
4.0 ± 0.2 4.1 ± 0.1
0.105 0.152
9.4 ± 0.1 9.3 ± 0.1
9.8 ± 0.2 9.6 ± 0.1
9.5 ± 0.1 9.5 ± 0.1
0.187 0.147
4.9 ± 0.05 4.8 ± 0.05
4.8 ± 0.06 4.7 ± 0.04
4.8 ± 0.03 4.7 ± 0.07
0.715 0.508
5.05 ± 0.6 6.4 ± 0.4
6.1 ± 0.5 6.0 ± 0.4
6.6 ± 0.4 6.5 ± 0.1
0.363 0.651
J Sci Food Agric 2016; 96: 602–609
© 2015 Society of Chemical Industry
wileyonlinelibrary.com/jsfa
605
CTRL, control group (non-supplemented); PO-225, goats offered 225 g of P. oceanica; PO-450, goats offered 450 g of P. oceanica. Significant variation among groups.
www.soci.org
d-ROM (CARR U)
A
C Castillo et al.
180 160 140 120 100 80 60 1
2
3
CTRL
SAC (µmol HClO mL–1)
B
4
5
6
7 PO-450
PO-225
750 700 650 600 550 500 450 400 350 300 1
2
3
CTRL
4
5
6
7 PO-450
PO-225
C 0.45 OSi (ROS/SAC)
0.4 0.35 0.3 0.25 0.2 0.15 0.1 1
2 CTRL
3
4 PO-225
5
6
7 PO-450
606
Figure 2. Mean redox parameters (± standard error) of goats in non-supplemented (CTRL) and Posidonia oceanica-supplemented (PO-225 and PO-450) groups during study (samplings 1–7). For serum d-ROM concentration (A), ANOVA indicated no effect of time (T) (P = 0.902), supplementation (TR) (P = 0.180) or T × TR interaction (P = 0.587). For serum SAC concentration (B), ANOVA indicated significant effects of T (P < 0.001) and TR (P < 0.001), while T × TR tended towards significance (P = 0.057). For OSi ratio (C), ANOVA indicated no effect of T (P = 0.355) or T × TR (P = 0.732) but showed TR (P = 0.005) to be an isolated factor.
wileyonlinelibrary.com/jsfa
© 2015 Society of Chemical Industry
J Sci Food Agric 2016; 96: 602–609
Posidonia oceanica in dairy goat nutrition
Glucose (mmol L–1)
A
www.soci.org
4.5 4 3.5 3
CTRL PO-225
2.5
PO-450
2 1
NEFA (mmol L–1)
B
2
3
4
5
6
0.8
7 CTRL
0.7
PO-225
0.6
PO-450
0.5 0.4 0.3 0.2 1
BHB (mmol L–1)
C
2
3
4
5
6
7
0.7 0.6 0.5 0.4 CTRL
0.3
PO-225 0.2
PO-450
0.1 1
2
3
4
5
6
7
Figure 3. Mean concentrations (± standard error) of parameters connected with energy metabolism of goats in non-supplemented (CTRL) and Posidonia oceanica-supplemented (PO-225 and PO-450) groups during study (samplings 1–7). For glucose (A), ANOVA indicated significant effects of time (T) (P < 0.001) and T × treatment (TR) interaction (P < 0.001) but not of TR (P = 0.295). For NEFA (B), ANOVA indicated significant effects of TR (P < 0.001), while T and T × TR tended towards significance (P = 0.055 and P = 0.090 respectively). For BHB (C), ANOVA indicated no effect of T (P = 0.385) but significant effects of TR (P = 0.003) and T × TR (P = 0.025).
J Sci Food Agric 2016; 96: 602–609
fat in the supplemented groups can be attributed to the fibre content of P. oceanica. In fact, salivation, as a result of mastication, can influence the production of acetate, which is a precursor of milk fat.12
Metabolic parameters Notably, all parameters assessed during the study period were within the physiological ranges described by di Trana et al.13 for
© 2015 Society of Chemical Industry
wileyonlinelibrary.com/jsfa
607
fibre might explain the numerically lower live weight shown by PO-450 goats in comparison with those in the other two groups; goats adapt their feeding behaviour to the diet they receive,12 suggesting that a new forage source should be introduced slowly, e.g. by mixing it with barley straw, in an attempt to avoid a decrease in intake and consequently in weight gain. It is clear that supplementation with P. oceanica had no detrimental effects on milk production, which decreased in all three groups as the lactation stage progressed. The higher proportion of milk
www.soci.org
C Castillo et al.
Table 3. Mean values (± standard error) of parameters connected with protein metabolism and enzymes studied Samplingb Parameter
Groupa
SUN (mmol L−1 )
CTRL PO-225 PO-450 CTRL PO-225 PO-450 CTRL PO-225 PO-450 CTRL PO-225 PO-450 CTRL PO-225 PO-450
Creatinine (mmol L−1 )
TSP (g L−1 )
AST (IU L−1 )
GGT (IU L−1 )
a
1 6.5 ± 0.5 8.2 ± 0.6 7.0 ± 0.6 67.4 ± 2.1 69.2 ± 1.2 67.4 ± 1.8 72.1 ± 1.4 73.4 ± 2.0 72.7 ± 1.7 71.1 ± 4.3 72.1 ± 3.3 78.0 ± 5.9 61.4 ± 9.2 52.1 ± 3.9 53.0 ± 1.7
2
3
7.9 ± 0.5 7.5 ± 0.4 7.5 ± 0.6 68.9 ± 1.6 64.6 ± 1.4 67.3 ± 2.3 73.3 ± 1.4 75.2 ± 2.0 69.7 ± 2.2 93.1 ± 7.7 77.8 ± 5.2 73.9 ± 7.3 49.1 ± 4.2 48.5 ± 3.2 53.4 ± 3.2
7.3 ± 0.6 7.1 ± 0.6 8.4 ± 0.8 64.6 ± 2.1 64.4 ± 2.1 67.5 ± 1.7 71.8 ± 1.8 73.0 ± 0.9 70.9 ± 2.7 83.3 ± 6.3 69.7 ± 5.7 82.0 ± 10.8 46.3 ± 2.4 55.2 ± 2.9 50.0 ± 3.1
4 6.7 ± 0.5 7.5 ± 0.7 7.5 ± 0.6 66.3 ± 2.0 67.1 ± 1.2 66.6 ± 2.4 73.7 ± 1.8 73.8 ± 1.7 73.9 ± 1.6 72.6 ± 5.1 85.8 ± 9.1 82.4 ± 7.1 56.3 ± 5.1 49.9 ± 3.3 47.6 ± 2.5
P valuec 5 8.2 ± 0.5 7.3 ± 0.5 8.0 ± 0.5 68.4 ± 1.1 65.7 ± 1.9 63.5 ± 1.5 74.6 ± 1.8 73.6 ± 1.9 68.6 ± 2.9 75.1 ± 5.6 80.8 ± 5.7 75.2 ± 3.9 48.9 ± 3.0 49.4 ± 2.2 56.9 ± 3.8
6 7.4 ± 0.4 6.9 ± 0.6 6.9 ± 0.4 66.5 ± 1.6 61.9 ± 2.2 67.2 ± 1.1 73.5 ± 1.8 68.6 ± 1.3 73.0 ± 1.8 77.4 ± 5.5 68.9 ± 6.1 80.8 ± 5.4 47.9 ± 1.5 58.3 ± 3.3 53.2 ± 3.8
7 6.9 ± 0.3 7.3 ± 0.6 7.2 ± 0.5 65.2 ± 2.4 62.8 ± 1.2 63.5 ± 2.2 73.7 ± 2.1 72.2 ± 1.8 74.5 ± 1.4 70.5 ± 5.7 78.9 ± 4.0 83.6 ± 5.8 51.6 ± 2.5 52.3 ± 2.3 52.7 ± 2.6
T
TR
T × TR
0.561
0.756
0.513
0.139
0.231
0.488
0.800
0.380
0.287
0.868
0.711
0.485
0.605
0.941
0.148
CTRL, control group (non-supplemented); PO-225, goats offered 225 g of P. oceanica; PO-450, goats offered 450 g of P. oceanica.
b 1, 112 DIM; 2, 119 DIM; 3, 126 DIM; 4, 133 DIM; 5, 140 DIM; 6, 147 DIM; 7, 154 DIM. c T, time; TR, treatment; T × TR, time × treatment interaction.
608
goats. This implies that P. oceanica consumption had no detrimental effects on the health of the animals. Therefore our aim here is to discuss the significant effects found, in relation to redox homeostasis and energy balance, and relate these to the productive results obtained in this experiment. OS plays an important role in regulating the metabolic activity of some organs and productivity in farm animals.14 According to our results, P. oceanica consumption did not increase free radical production, as indicated by serum d-ROM levels, but affected antioxidant reserves, as shown by serum SAC activities. The PO-450 group showed higher antioxidant activity from the third sampling onwards. Various classes of secondary metabolites have been reported in P. oceanica, such as phenolic compounds, predominantly caffeic acid, flavonoids and, more recently, posidozinol, a novel methylated sesquiterpene.15 – 18 These compounds are known for their defensive and antioxidant properties and might explain the lower SCC in milk of P. oceanica-supplemented goats than in CTRL goats. In addition, flavonoids reduce the occurrence of udder infections and improve the quality of their production, in terms of the number of somatic cells and fat. All these properties confer an added value to the product as a source of antioxidants for the human diet.19 The OSi ratio provides an objective assessment of the relationship between oxidants and antioxidants; thus an increase in this ratio indicates a risk of OS due to the increase in oxidant production and/or defensive antioxidant consumption.8 According to this concept, the risk of OS, as indicated by the OSi ratio,8 was lower in supplemented goats, confirming the beneficial effects of antioxidants in animal health. Further studies which consider a transition period, where the risk of OS has been demonstrated in goats,20 could contribute to the assessment of the potential benefits of P. oceanica in metabolic disturbances associated with this stage. It has been shown that P. oceanica extract affects the glucose balance of diabetic rats by decreasing blood glucose.21 We did not observe this pattern, and glucose levels were not associated with negative effects. Blood concentrations of NEFA are closely linked to energy balance, and BHB, a ketone body, is an
wileyonlinelibrary.com/jsfa
intermediate metabolite of fatty acid oxidation. On the other hand, a high-fibre dietary intake promotes the production of acetate as well as butyric and isobutyric acids in the rumen and dictates changes in their metabolism. Thus, taking into account the NEFA values of supplemented goats and their significance, the higher BHB concentrations observed could be attributable to higher production of volatile fatty acids. Finally, as the level of creatinine remained within the reference values13,20 throughout the study, no impact of renal function on SUN was expected, and thus the urea concentration in serum reflected the ammonia concentration in the rumen and the protein content in the diet. These results suggest that goats fed P. oceanica had no disturbance in protein metabolism during the study, independently of the dosage. The activities of AST and GGT are discussed together, as they are usually used to assess liver function and are relevant when new dietary supplements are given to ruminants.19 Similarly to components of protein metabolism, both enzymes remained within the physiological range of variations for goats, implying that supplementation with P. oceanica had no detrimental effects on liver function.
CONCLUSION Substitution of barley by P. oceanica increased milk fat content without affecting health and milk production. The leaves of P. oceanica can be used as a source of forage in goat feeding. Further studies should be conducted to address various questions, e.g. the mechanism of action of phytochemicals contained in this marine plant in rumen dynamics and the appropriate form of administration in ruminant diets, and also to assess these effects in other complex physiological stages such as the transition period.
ACKNOWLEDGEMENTS The authors express their gratitude to the CESPA-FERROVIAL Funds for the financial support for carrying out this work, via the
© 2015 Society of Chemical Industry
J Sci Food Agric 2016; 96: 602–609
Posidonia oceanica in dairy goat nutrition
www.soci.org
project ‘Subproductos marinos en nutrición animal: utilidad de los arribazones de P. oceanica como fuente de fibra en ganado caprino de leche (Ref. 15.271)’, and to the Council of S. Javier (Murcia, SE Spain) for the facilities provided for the study. The funder played no role in the implementation of the study, collection, analysis and interpretation of data, nor in the preparation or approval of the manuscript. The authors gratefully thank Lucía Casanova Iglesias for her technical assistance and acknowledge the support of the Galician Government (Xunta de Galicia) under grant CN2012/327. Angel Abuelo holds an FPU fellowship (Ref. AP2010-0013) from the Spanish Ministry of Education, Culture and Sports.
REFERENCES 1 Castel JM, Mena Y, Delgado-Pertiñez M, Camuñez J, Basulto J, Caravaca F et al., Characterization of semi-extensive goat production systems in southern Spain. Small Ruminant Res 47:133–143 (2003). 2 Blache D, Maloney SK and Revell DK, Use and limitations of alternative feed resources to sustain and improve reproductive performance in sheep and goats. Anim Feed Sci Technol 147:140–157 (2008). 3 Castillo C, Mantecón AR, Sotillo J, Benedito JL, Abuelo A, Gutiérrez C et al., The use of banquettes of Posidonia oceanica as a source of fibre and minerals in ruminant nutrition. An observational study. Animal 8:1663–1666 (2014). 4 Calsamiglia S, Ferret A and Bach A, Tablas FEDNA de Valor Nutritivo de Forrajes y Subproductos Fibrosos Húmedos [Online]. Fundación para el Desarrollo de la Nutrición Animal (2004). Available: http://www.fundacionfedna.org/forrajes/introducci%C3%B3n-forra jes [11 November 2012]. 5 Federación Española de Asociaciones de Ganado Selecto (FEAGAS). [Online]. Available: http://feagas.com/index.php/es/razas/especiecaprina/murciana-granadina [10 September 2014]. 6 Trotti R, Carratelli M, Barbieri M, Micieli G, Bosone D, Rondanelli M et al., Oxidative stress and a thrombophilic condition in alcoholics without severe liver disease. Haematologica 86:85–91 (2001). 7 Trotti R, Caratelli M and Barbieri M, Performance and clinical application of a new, fast method for the detection of hydroperoxides in serum. Panminerva Med 44:37–40 (2002).
8 Abuelo A, Hernandez J, Benedito JL and Castillo C, Oxidative stress index (OSi) as a new tool to assess redox status in dairy cattle during the transition period. Animal 7:1374–1378 (2013). 9 Garcia-Gonzalez R, Giraldez FJ, Mantecón AR, Gonzalez JS and Lopez S, Effects of rhubarb (Rheum spp.) and frangula (Frangula alnus) on intake, digestibility and ruminal fermentation of different diets and feedstuffs by sheep. Anim Feed Sci Technol 176:131–139 (2012). 10 AOAC, Official Methods of Analysis, 16th edition. Association of Official Analytical Chemists, Arlington, VA (1999). 11 Van Soest PJ, Limiting factors in plant residues of low biodegradability. Agric Environ 6:135–143 (1981). 12 Abijaoude JA, Morand-Fehr P, Tessier J, Schmidely PH and Sauvant D, Diet effect on the daily feeding behaviour, frequency and characteristics of meals in dairy goats. Livest Prod Sci 64:29–37 (2000). 13 Di Trana A, Celi P, Claps S, Fedele V and Rubino R, The effect of hot season and nutrition on the oxidative status and metabolic profile in dairy goats during mid lactation. Anim Sci 82:717–722 (2006). 14 Castillo C, Pereira V, Abuelo A and Hernández J, Effect of supplementation with antioxidants on the quality of bovine milk and meat production. Sci World J 2013:616098 (2013). 15 Dumay O, Costa J, Desjobert JM and Pergent G, Variations in the concentration of phenolic compounds in the seagrass Posidonia oceanica under conditions of competition. Phytochemistry 65:3211–3220 (2004). 16 Haznedaroglu MZ and Zeybek U, HPLC determination of chicoric acid in leaves of Posidonia oceanica. Pharmaceut Biol 45:745–748 (2007). 17 Heglmeier A and Zidorn C, Secondary metabolites of Posidonia oceanica (Posidoniaceae). Biochem Syst Ecol 38:964–970 (2010). 18 Hammami S, Salem AB, Ashour ML, Cheriaa J, Graziano G and Mighri Z, A novel methylated sesquiterpene from seagrass Posidonia oceanica (L.) Delile. Nat Prod Res 27:1265–1270 (2013). 19 Castillo C, Hernandez J, Pereira V and Benedito JL, Update about nutritional strategies in feedlot for preventing ruminal acidosis, in Advances in Zoology Research, Vol. 4, ed. by Jenkins OP. Nova Science Publishers, New York, NY, pp. 1–84 (2012). 20 Celi P, di Trana A and Claps S, Effects of plane of nutrition on oxidative stress in goats during the peripartum period. Vet J 184:95–99 (2010). 21 Gokce G and Haznedaroglu MZ, Evaluation of antidiabetic, antioxidant and vasoprotective effects of Posidonia oceanica extract. J Ethnopharmacol 115:122–130 (2008).
609
J Sci Food Agric 2016; 96: 602–609
© 2015 Society of Chemical Industry
wileyonlinelibrary.com/jsfa
Revised: 5 February 2015
Accepted article published: 10 February 2015
Published online in Wiley Online Library: 25 February 2015
(wileyonlinelibrary.com) DOI 10.1002/jsfa.7129
Posidonia oceanica banquettes as a substitute for straw in dairy goat rations: metabolic and productive effects Cristina Castillo,a* Angel R Mantecón,b Juan Sotillo,c Cándido Gutiérrez,c Angel Abueloa and Joaquín Hernándeza Abstract BACKGROUND: The marine plant Posidonia oceanica (L.) Delile can be a source of fibre to increase the efficiency of product costs. The aim of the present study was to assess the productive (milk production and performance) and metabolic (blood metabolites) effects of P. oceanica in the ration of dairy goats as a substitute for straw. Posidonia oceanica was used at 225 and 450 g day−1 per goat in lieu of barley straw. RESULT: Supplementation with P. oceanica had no detrimental effects on the body weight, milk production and metabolic status of goats. Goats fed P. oceanica produced more milk fat, had a lower somatic cell count in their milk and showed a decreased risk of oxidative stress. CONCLUSION: Goats can be fed P oceanica at levels of up to 450 g day−1 without detrimental effects on milk production and health, therefore P. oceanica can be a substitute for barley straw in the nutrition of goats. © 2015 Society of Chemical Industry Keywords: goats; Posidonia oceanica; production; metabolism; oxidative stress
INTRODUCTION
602
A major characteristic of goat production in the Mediterranean area is its dependence on pasture land.1 In these semi-arid areas, animal production is increasingly reliant on supplemental feeding. The cost of many traditional feeds restricts their use in many countries, and producers are turning to alternative feed sources.2 One of them, especially in Mediterranean countries, is marine plants. Posidonia oceanica (L) Delile is a seagrass that is widely distributed along Mediterranean coastlines. This marine plant is more complex in evolutionary terms than algae. When leaves of P. oceanica are not functional, they lose their green colour and become brown, whereupon they subsequently break off and are carried to the coast, appearing as ‘banquettes’. Recent studies have demonstrated that these wastes could have an important role in the feed of ruminants as a source of fibre,3 which could help to optimise production costs. The chemical composition of P. oceanica banquettes shows a higher ash content and lignin fraction than cereal straw.4 Additionally, the content of neutral detergent fibre in P. oceanica suggests a potentially positive effect for animals that consume high-grain diets, by promoting salivation and chewing activity. Despite these promising results, to our knowledge, there are no studies concerning the effects (in terms of production and/or animal health) of introducing these banquettes as a component of the ruminant diet. The farming system in the Murcia region of southeast Spain is mainly based on goat husbandry, especially the Murciano-Granadina breed. With an annual yield of 35 million J Sci Food Agric 2016; 96: 602–609
litres (some individuals have reached a mean milk production of about 1.3 kg day−1 over 305 days of lactation), the milk of Murciano-Granadina goats is characterised by a fat content of 5.4 g, a protein content of 3.6 g and a dry extract content of 14.5 g per 100 g and is considered highly suited for the production of different varieties of cheeses.5 Based on our previous results on the chemical composition of P. oceanica,3 the aim of the present study was to assess the effects of introducing P. oceanica as a substitute for straw in the feed of dairy goats on milk production and metabolism (blood metabolites, including oxidative stress).
METHODS Collection of P. oceanica samples In compliance with protection rules (Dir. 92/43/CEE) for areas within the Natura-2000 Network, permission for sampling was
∗
Correspondence to: Cristina Castillo, Departamento de Patología Animal, Facultad de Veterinaria, Universidad de Santiago de Compostela, E-27002 Lugo, Spain. E-mail: [email protected]
a Departamento de Patología Animal, Facultad de Veterinaria, Universidad de Santiago de Compostela, E-27002 Lugo, Spain b Instituto de Ganadería de Montaña, CSIC-ULE, Finca Marzanas, E-24346 Grulleros-León, Spain c Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad de Murcia, Murcia, Spain
www.soci.org
© 2015 Society of Chemical Industry
Posidonia oceanica in dairy goat nutrition
www.soci.org
obtained from the local government. The study was conducted at La Manga beach (37∘ 38′ –37∘ 50′ N, 0∘ 41′ –0∘ 52′ W) located in Murcia (southeast Spain). Samples of banquettes of P. oceanica were collected on the same day directly from the beach, above the water line; these were washed with distilled water and sun dried for 48 h in a warehouse. Subsequently, leaves were supplied to the experimental animals. Animals Twenty-four multiparous Murciano-Granadina non-pregnant dairy goats (4.0 years old, mean weight 42.5 kg) in the late-lactation stage were used for the study. We chose females that were in the late-lactation stage so that neither pregnancy nor milk yield could condition blood parameters. The study was conducted in the Murcian Institute of Investigation and Agricultural Development (IMIDA). During the experiment, each group was kept and fed in a separate pen. All goats were housed in a building with a partially controlled environment (the temperature varied between 16 and 20 ∘ C). Throughout the study, the animals were cared for and managed in accordance with official Spanish guidelines on animal care. Experimental design and animal treatments The study period was from week 16 of lactation (112 days in milk (DIM)) until week 22 (154 DIM), in the declining phase of the lactation curve and 15 days prior to oestrus induction and synchronisation for subsequent artificial insemination. The goats were randomly divided into three equal groups of eight. An individual goat received daily 1.4 kg of concentrate (Cargill Animal Nutrition, Torre Pacheco, Murcia, Spain) (Table 1) and 400 g of alfalfa hay. In addition to concentrate and alfalfa hay, the goats of the control (CTRL) group were offered 450 g of barley straw, which was substituted by 225 and 450 g of P. oceanica in the PO-225 and PO-450 groups of goats respectively. The chemical
contents of P. oceanica, barley straw and alfalfa hay are listed in Table 1. Concentrate and alfalfa hay were offered in the same container simultaneously to each pen in two equal portions at 09:30 and 14:00. Water was available ad libitum. Forage refusals (straw and/or P. oceanica) were collected at 07:30 before the distribution of fresh feed and were subsequently weighed. Concentrate and alfalfa hay refusals were non-existent in the three pens. Individual goats were weighed weekly throughout the trial. All procedures and protocols were approved by the Ethical Committee of the Faculty of Veterinary Medicine (Murcia University). Sampling collection Blood samples were collected by jugular venepuncture (Vacutainer® tubes without EDTA) at 112 DIM, prior to the introduction of P. oceanica into the diet (sampling 1), and every week at 119 (sampling 2), 126 (sampling 3), 133 (sampling 4), 140 (sampling 5), 147 (sampling 6) and 154 (sampling 7) days after milking and prior to feeding, between 08:30 and 09:00. Mean body weight and mean milk production were recorded on the same day, prior to blood sampling. Milk samples were obtained from each goat using sterile vials with preservative (azidiol), and these were refrigerated at 4 ∘ C. Biochemical determinations Blood samples were centrifuged (2000 × g for 20 min) and the serum was immediately frozen (−20 ∘ C) for subsequent analysis. Serum glucose, 𝛽-hydroxybutyrate (BHB), serum urea nitrogen (SUN), creatinine, total serum proteins (TSP), aspartate aminotransferase (AST) and 𝛾-glutamyl transferase (GGT) were measured using standardised diagnostic kits from RAL (RAL Técnica para el Laboratorio SA, Barcelona, Spain). Non-esterified fatty acids (NEFA) were assayed using a kit from Wako Chemicals GmbH (Neuss, Germany). In all cases, appropriate controls were
Table 1. Composition of concentrate and chemical composition of concentrate and feeds Ingredients of concentrate (g kg−1 DM) Wheat bran Soy bean Barley Malt Sunflower oil (30%) Rye Honey bean Corn flour Cane molasses Calcium carbonate Vitamin/mineral premixa
266.5 250 150 80 70 69.9 41.6 36.7 10 14.9 10.4
Chemical composition (g kg−1 DM)
Concentrate
Barley straw
Alfalfa hay
P. oceanica
Crude protein (CP) Neutral detergent fibre (NDF) Acid detergent fibre (ADF) Acid detergent lignin (ADL) Ether extract (EE) Ash Net energy of lactation (Mcal kg−1 )
175.5 366.4 190.8 – 30.9 76.0 1.5
3.7 72 46.4 8.4 1.6 7.2 –
17.0 49.5 24.5 8.0 2.0 11.2 –
4.1 70.4 55.8 11.4 1.4 17.6 –
J Sci Food Agric 2016; 96: 602–609
© 2015 Society of Chemical Industry
wileyonlinelibrary.com/jsfa
603
DM, dry matter. a Premix contained 10 g Ca, 5.7 g P, 3.4 g Mg, 0.72 mg Se, 154 mg Zn, 14 900 IU vitamin A and 3100 IU vitamin D kg−1 DM.
www.soci.org used. Physiological and pathological control sera were analysed alongside the samples for two-point quality control. Serum antioxidant capacity (SAC) was measured as described by Trotti et al.6 using an OXY-Adsorbent test kit (Diacron International, Grosseto, Italy); the results are expressed as μmol HClO mL−1 . Reactive oxygen substances (ROS) were assayed using the standardised spectrophotometric d-ROM test (Diacron International);7 the results are expressed in arbitrary ‘Carratelli units’ (CARR U), with 1 CARR U corresponding to 0.08 mg per 100 mL H2 O2 . The oxidative stress index (OSi) was calculated as ROS/SAC.8
A
C Castillo et al.
The chemical composition of milk (protein, fat, lactose, non-fatty solids (NFS)) was determined using an infrared spectrophotometer (Milko Skan S 50B, Foss Electric, Hillerød, Denmark), and somatic cell counts (SCC) were obtained using a Fossomatic 80 (Foss Electric). The analytical procedures for determining the chemical composition of forage were described previously.9 The ash and N contents of P. oceanica, barley straw and alfalfa hay were analysed following AOAC methods 942.05 and 984.13 respectively.10 Neutral detergent fibre (NDF) was analysed according to the procedure of Van
CTRL
49
PO-225
Live weight (Kilograms)
47
PO-450
45 43 41 39 37 35 1
Milk production (Kilograms)
B
2
3
4
5
6
7
2.5
2
1.5
1 CTRL PO-225
0.5
PO-450 0 1
2
3
4
5
6
7
604
Figure 1. Mean live weight and milk production (± standard error) of goats in non-supplemented (CTRL) and Posidonia oceanica-supplemented (PO-225 and PO-450) groups during study (samplings 1–7). For live weight (A), ANOVA indicated a significant effect of time (T) (P < 0.001) but not of supplementation (TR) (P = 0.833) or T × TR interaction (P = 0.294). For milk production (B), ANOVA indicated significant effects of T (P < 0.001) and T × TR (P = 0.001) but not of TR (P = 0.862).
wileyonlinelibrary.com/jsfa
© 2015 Society of Chemical Industry
J Sci Food Agric 2016; 96: 602–609
Posidonia oceanica in dairy goat nutrition
www.soci.org
Soest.11 Samples were weighed in F57 Ankom filter bags (Ankom Technology Corp., Macedon, NY, USA) and washed at 100 ∘ C for 1 h with neutral detergent in an Ankom fibre analyser (Ankom Technology Corp.). Sodium sulfite and a heat-stable amylase were used in the analysis of NDF, which was expressed inclusive of residual ash. Acid detergent fibre (ADF) and acid detergent lignin (ADL) were determined in the bags containing residual NDF in an Ankom fibre analyser according to AOAC method 973.18.10 Statistical analysis Data were tested for normal distribution using the Shapiro–Wilk test. Serum parameters and live parameters (mean live weight and milk production) were subjected to analysis of variance (ANOVA) with ‘group’ as the fixed main effect and ‘sampling date’ as a repeated measure effect; thus the model considered the effects of treatment (TR), time (T) and the T × TR interaction. SCC were normalised by log10 transformation. Differences in milk composition parameters between groups at the beginning (112 DIM, sampling 1) and end (154 DIM, sampling 7) of the experiment were determined by ANOVA. All statistical analyses were performed using the SPSS 19 package (SPSS Inc., Chicago, IL, USA). Bonferroni corrections were included for post hoc analysis. Significance was defined by P < 0.05 and trends at 0.05 < P < 0.1.
RESULTS Intake and milk production The mean daily intake of forage (straw or P. oceanica, excluding alfalfa hay) was 300 g of barley straw per goat in the CTRL group and 126 g of P. oceanica per goat in the PO-450 group (fed only the marine plant). In the PO-225 group the mean daily intake was 187 g of barley straw and 47 g of P. oceanica per animal. Production parameters such as body weight and milk production are shown in Fig. 1. Supplementation with the marine plant had no significant effect on body weight and milk production. A progressive and significant decrease in milk production was observed during the study.
Goats fed either level of P. oceanica had higher levels of milk fat, and this increase was greater in the PO-225 group (Table 2). Other quality attributes of milk (protein, NFS, lactose and SCC) were not affected by P. oceanica supplementation. Metabolic parameters Antioxidant production was significantly influenced by the time course and also by supplementation with P. oceanica (Fig. 2). Goats fed P. oceanica ended the study with higher SAC than CTRL goats. In addition, animals of the PO-450 group showed higher antioxidant activity than animals of the PO-225 group. Considering OSi ratios, supplemented goats ended the study with lower oxidative stress (OS) risk than CTRL goats, especially animals of the PO-450 group. Figure 3 presents the evolution of the energy-related parameters during the study period. Concentrations of glucose fluctuated without a clear pattern among the three groups, and all goats had similar glucose levels. NEFA concentrations in both PO-225 and PO-450 goats were lower than in CTRL goats. BHB concentrations in the CTRL group increased progressively throughout the experiment, whereas the PO-225 and PO-450 groups maintained higher and more stable BHB levels, except for the last sampling, where CTRL and PO-450 goats had higher BHB concentrations than PO-225 goats. The levels of SUN, creatinine and TSP and the activities of AST and GGT were similar among the three goat groups (Table 3).
DISCUSSION Productive values There were no refusals of concentrate and alfalfa hay by animals in the three pens, so only mean ingestion of the other types of forage was registered. The PO-225 group consumed higher amounts of barley straw than P. oceanica leaves, which could be attributable to a selective effect of the animals against the new feedstuff. In fact, goats of the PO-450 group were those who consumed the least amount of forage. This difference in the amount of ingested
Table 2. Mean values (± standard deviation) of milk components at beginning (sampling 1, 112 DIM) and end (sampling 7, 154 DIM) of study and effects of ANOVA Groupa Item Fat (g per 100 g) Sampling 1 Sampling 7b Protein (g per 100 g) Sampling 1 Sampling 7 NFS (g per 100 g) Sampling 1 Sampling 7 Lactose (g per 100 g) Sampling 1 Sampling 7 SCC (log10 ) Sampling 1 Sampling 7 a b
CTRL
PO-225
PO-450
P value
4.6 ± 0.2 4.7 ± 0.7a
5.3 ± 1.2 6.1 ± 0.9b
5.2 ± 0.8 5.9 ± 0.8b
0.309 0.006
3.8 ± 0.1 3.8 ± 0.1
4.3 ± 0.2 4.2 ± 0.9
4.0 ± 0.2 4.1 ± 0.1
0.105 0.152
9.4 ± 0.1 9.3 ± 0.1
9.8 ± 0.2 9.6 ± 0.1
9.5 ± 0.1 9.5 ± 0.1
0.187 0.147
4.9 ± 0.05 4.8 ± 0.05
4.8 ± 0.06 4.7 ± 0.04
4.8 ± 0.03 4.7 ± 0.07
0.715 0.508
5.05 ± 0.6 6.4 ± 0.4
6.1 ± 0.5 6.0 ± 0.4
6.6 ± 0.4 6.5 ± 0.1
0.363 0.651
J Sci Food Agric 2016; 96: 602–609
© 2015 Society of Chemical Industry
wileyonlinelibrary.com/jsfa
605
CTRL, control group (non-supplemented); PO-225, goats offered 225 g of P. oceanica; PO-450, goats offered 450 g of P. oceanica. Significant variation among groups.
www.soci.org
d-ROM (CARR U)
A
C Castillo et al.
180 160 140 120 100 80 60 1
2
3
CTRL
SAC (µmol HClO mL–1)
B
4
5
6
7 PO-450
PO-225
750 700 650 600 550 500 450 400 350 300 1
2
3
CTRL
4
5
6
7 PO-450
PO-225
C 0.45 OSi (ROS/SAC)
0.4 0.35 0.3 0.25 0.2 0.15 0.1 1
2 CTRL
3
4 PO-225
5
6
7 PO-450
606
Figure 2. Mean redox parameters (± standard error) of goats in non-supplemented (CTRL) and Posidonia oceanica-supplemented (PO-225 and PO-450) groups during study (samplings 1–7). For serum d-ROM concentration (A), ANOVA indicated no effect of time (T) (P = 0.902), supplementation (TR) (P = 0.180) or T × TR interaction (P = 0.587). For serum SAC concentration (B), ANOVA indicated significant effects of T (P < 0.001) and TR (P < 0.001), while T × TR tended towards significance (P = 0.057). For OSi ratio (C), ANOVA indicated no effect of T (P = 0.355) or T × TR (P = 0.732) but showed TR (P = 0.005) to be an isolated factor.
wileyonlinelibrary.com/jsfa
© 2015 Society of Chemical Industry
J Sci Food Agric 2016; 96: 602–609
Posidonia oceanica in dairy goat nutrition
Glucose (mmol L–1)
A
www.soci.org
4.5 4 3.5 3
CTRL PO-225
2.5
PO-450
2 1
NEFA (mmol L–1)
B
2
3
4
5
6
0.8
7 CTRL
0.7
PO-225
0.6
PO-450
0.5 0.4 0.3 0.2 1
BHB (mmol L–1)
C
2
3
4
5
6
7
0.7 0.6 0.5 0.4 CTRL
0.3
PO-225 0.2
PO-450
0.1 1
2
3
4
5
6
7
Figure 3. Mean concentrations (± standard error) of parameters connected with energy metabolism of goats in non-supplemented (CTRL) and Posidonia oceanica-supplemented (PO-225 and PO-450) groups during study (samplings 1–7). For glucose (A), ANOVA indicated significant effects of time (T) (P < 0.001) and T × treatment (TR) interaction (P < 0.001) but not of TR (P = 0.295). For NEFA (B), ANOVA indicated significant effects of TR (P < 0.001), while T and T × TR tended towards significance (P = 0.055 and P = 0.090 respectively). For BHB (C), ANOVA indicated no effect of T (P = 0.385) but significant effects of TR (P = 0.003) and T × TR (P = 0.025).
J Sci Food Agric 2016; 96: 602–609
fat in the supplemented groups can be attributed to the fibre content of P. oceanica. In fact, salivation, as a result of mastication, can influence the production of acetate, which is a precursor of milk fat.12
Metabolic parameters Notably, all parameters assessed during the study period were within the physiological ranges described by di Trana et al.13 for
© 2015 Society of Chemical Industry
wileyonlinelibrary.com/jsfa
607
fibre might explain the numerically lower live weight shown by PO-450 goats in comparison with those in the other two groups; goats adapt their feeding behaviour to the diet they receive,12 suggesting that a new forage source should be introduced slowly, e.g. by mixing it with barley straw, in an attempt to avoid a decrease in intake and consequently in weight gain. It is clear that supplementation with P. oceanica had no detrimental effects on milk production, which decreased in all three groups as the lactation stage progressed. The higher proportion of milk
www.soci.org
C Castillo et al.
Table 3. Mean values (± standard error) of parameters connected with protein metabolism and enzymes studied Samplingb Parameter
Groupa
SUN (mmol L−1 )
CTRL PO-225 PO-450 CTRL PO-225 PO-450 CTRL PO-225 PO-450 CTRL PO-225 PO-450 CTRL PO-225 PO-450
Creatinine (mmol L−1 )
TSP (g L−1 )
AST (IU L−1 )
GGT (IU L−1 )
a
1 6.5 ± 0.5 8.2 ± 0.6 7.0 ± 0.6 67.4 ± 2.1 69.2 ± 1.2 67.4 ± 1.8 72.1 ± 1.4 73.4 ± 2.0 72.7 ± 1.7 71.1 ± 4.3 72.1 ± 3.3 78.0 ± 5.9 61.4 ± 9.2 52.1 ± 3.9 53.0 ± 1.7
2
3
7.9 ± 0.5 7.5 ± 0.4 7.5 ± 0.6 68.9 ± 1.6 64.6 ± 1.4 67.3 ± 2.3 73.3 ± 1.4 75.2 ± 2.0 69.7 ± 2.2 93.1 ± 7.7 77.8 ± 5.2 73.9 ± 7.3 49.1 ± 4.2 48.5 ± 3.2 53.4 ± 3.2
7.3 ± 0.6 7.1 ± 0.6 8.4 ± 0.8 64.6 ± 2.1 64.4 ± 2.1 67.5 ± 1.7 71.8 ± 1.8 73.0 ± 0.9 70.9 ± 2.7 83.3 ± 6.3 69.7 ± 5.7 82.0 ± 10.8 46.3 ± 2.4 55.2 ± 2.9 50.0 ± 3.1
4 6.7 ± 0.5 7.5 ± 0.7 7.5 ± 0.6 66.3 ± 2.0 67.1 ± 1.2 66.6 ± 2.4 73.7 ± 1.8 73.8 ± 1.7 73.9 ± 1.6 72.6 ± 5.1 85.8 ± 9.1 82.4 ± 7.1 56.3 ± 5.1 49.9 ± 3.3 47.6 ± 2.5
P valuec 5 8.2 ± 0.5 7.3 ± 0.5 8.0 ± 0.5 68.4 ± 1.1 65.7 ± 1.9 63.5 ± 1.5 74.6 ± 1.8 73.6 ± 1.9 68.6 ± 2.9 75.1 ± 5.6 80.8 ± 5.7 75.2 ± 3.9 48.9 ± 3.0 49.4 ± 2.2 56.9 ± 3.8
6 7.4 ± 0.4 6.9 ± 0.6 6.9 ± 0.4 66.5 ± 1.6 61.9 ± 2.2 67.2 ± 1.1 73.5 ± 1.8 68.6 ± 1.3 73.0 ± 1.8 77.4 ± 5.5 68.9 ± 6.1 80.8 ± 5.4 47.9 ± 1.5 58.3 ± 3.3 53.2 ± 3.8
7 6.9 ± 0.3 7.3 ± 0.6 7.2 ± 0.5 65.2 ± 2.4 62.8 ± 1.2 63.5 ± 2.2 73.7 ± 2.1 72.2 ± 1.8 74.5 ± 1.4 70.5 ± 5.7 78.9 ± 4.0 83.6 ± 5.8 51.6 ± 2.5 52.3 ± 2.3 52.7 ± 2.6
T
TR
T × TR
0.561
0.756
0.513
0.139
0.231
0.488
0.800
0.380
0.287
0.868
0.711
0.485
0.605
0.941
0.148
CTRL, control group (non-supplemented); PO-225, goats offered 225 g of P. oceanica; PO-450, goats offered 450 g of P. oceanica.
b 1, 112 DIM; 2, 119 DIM; 3, 126 DIM; 4, 133 DIM; 5, 140 DIM; 6, 147 DIM; 7, 154 DIM. c T, time; TR, treatment; T × TR, time × treatment interaction.
608
goats. This implies that P. oceanica consumption had no detrimental effects on the health of the animals. Therefore our aim here is to discuss the significant effects found, in relation to redox homeostasis and energy balance, and relate these to the productive results obtained in this experiment. OS plays an important role in regulating the metabolic activity of some organs and productivity in farm animals.14 According to our results, P. oceanica consumption did not increase free radical production, as indicated by serum d-ROM levels, but affected antioxidant reserves, as shown by serum SAC activities. The PO-450 group showed higher antioxidant activity from the third sampling onwards. Various classes of secondary metabolites have been reported in P. oceanica, such as phenolic compounds, predominantly caffeic acid, flavonoids and, more recently, posidozinol, a novel methylated sesquiterpene.15 – 18 These compounds are known for their defensive and antioxidant properties and might explain the lower SCC in milk of P. oceanica-supplemented goats than in CTRL goats. In addition, flavonoids reduce the occurrence of udder infections and improve the quality of their production, in terms of the number of somatic cells and fat. All these properties confer an added value to the product as a source of antioxidants for the human diet.19 The OSi ratio provides an objective assessment of the relationship between oxidants and antioxidants; thus an increase in this ratio indicates a risk of OS due to the increase in oxidant production and/or defensive antioxidant consumption.8 According to this concept, the risk of OS, as indicated by the OSi ratio,8 was lower in supplemented goats, confirming the beneficial effects of antioxidants in animal health. Further studies which consider a transition period, where the risk of OS has been demonstrated in goats,20 could contribute to the assessment of the potential benefits of P. oceanica in metabolic disturbances associated with this stage. It has been shown that P. oceanica extract affects the glucose balance of diabetic rats by decreasing blood glucose.21 We did not observe this pattern, and glucose levels were not associated with negative effects. Blood concentrations of NEFA are closely linked to energy balance, and BHB, a ketone body, is an
wileyonlinelibrary.com/jsfa
intermediate metabolite of fatty acid oxidation. On the other hand, a high-fibre dietary intake promotes the production of acetate as well as butyric and isobutyric acids in the rumen and dictates changes in their metabolism. Thus, taking into account the NEFA values of supplemented goats and their significance, the higher BHB concentrations observed could be attributable to higher production of volatile fatty acids. Finally, as the level of creatinine remained within the reference values13,20 throughout the study, no impact of renal function on SUN was expected, and thus the urea concentration in serum reflected the ammonia concentration in the rumen and the protein content in the diet. These results suggest that goats fed P. oceanica had no disturbance in protein metabolism during the study, independently of the dosage. The activities of AST and GGT are discussed together, as they are usually used to assess liver function and are relevant when new dietary supplements are given to ruminants.19 Similarly to components of protein metabolism, both enzymes remained within the physiological range of variations for goats, implying that supplementation with P. oceanica had no detrimental effects on liver function.
CONCLUSION Substitution of barley by P. oceanica increased milk fat content without affecting health and milk production. The leaves of P. oceanica can be used as a source of forage in goat feeding. Further studies should be conducted to address various questions, e.g. the mechanism of action of phytochemicals contained in this marine plant in rumen dynamics and the appropriate form of administration in ruminant diets, and also to assess these effects in other complex physiological stages such as the transition period.
ACKNOWLEDGEMENTS The authors express their gratitude to the CESPA-FERROVIAL Funds for the financial support for carrying out this work, via the
© 2015 Society of Chemical Industry
J Sci Food Agric 2016; 96: 602–609
Posidonia oceanica in dairy goat nutrition
www.soci.org
project ‘Subproductos marinos en nutrición animal: utilidad de los arribazones de P. oceanica como fuente de fibra en ganado caprino de leche (Ref. 15.271)’, and to the Council of S. Javier (Murcia, SE Spain) for the facilities provided for the study. The funder played no role in the implementation of the study, collection, analysis and interpretation of data, nor in the preparation or approval of the manuscript. The authors gratefully thank Lucía Casanova Iglesias for her technical assistance and acknowledge the support of the Galician Government (Xunta de Galicia) under grant CN2012/327. Angel Abuelo holds an FPU fellowship (Ref. AP2010-0013) from the Spanish Ministry of Education, Culture and Sports.
REFERENCES 1 Castel JM, Mena Y, Delgado-Pertiñez M, Camuñez J, Basulto J, Caravaca F et al., Characterization of semi-extensive goat production systems in southern Spain. Small Ruminant Res 47:133–143 (2003). 2 Blache D, Maloney SK and Revell DK, Use and limitations of alternative feed resources to sustain and improve reproductive performance in sheep and goats. Anim Feed Sci Technol 147:140–157 (2008). 3 Castillo C, Mantecón AR, Sotillo J, Benedito JL, Abuelo A, Gutiérrez C et al., The use of banquettes of Posidonia oceanica as a source of fibre and minerals in ruminant nutrition. An observational study. Animal 8:1663–1666 (2014). 4 Calsamiglia S, Ferret A and Bach A, Tablas FEDNA de Valor Nutritivo de Forrajes y Subproductos Fibrosos Húmedos [Online]. Fundación para el Desarrollo de la Nutrición Animal (2004). Available: http://www.fundacionfedna.org/forrajes/introducci%C3%B3n-forra jes [11 November 2012]. 5 Federación Española de Asociaciones de Ganado Selecto (FEAGAS). [Online]. Available: http://feagas.com/index.php/es/razas/especiecaprina/murciana-granadina [10 September 2014]. 6 Trotti R, Carratelli M, Barbieri M, Micieli G, Bosone D, Rondanelli M et al., Oxidative stress and a thrombophilic condition in alcoholics without severe liver disease. Haematologica 86:85–91 (2001). 7 Trotti R, Caratelli M and Barbieri M, Performance and clinical application of a new, fast method for the detection of hydroperoxides in serum. Panminerva Med 44:37–40 (2002).
8 Abuelo A, Hernandez J, Benedito JL and Castillo C, Oxidative stress index (OSi) as a new tool to assess redox status in dairy cattle during the transition period. Animal 7:1374–1378 (2013). 9 Garcia-Gonzalez R, Giraldez FJ, Mantecón AR, Gonzalez JS and Lopez S, Effects of rhubarb (Rheum spp.) and frangula (Frangula alnus) on intake, digestibility and ruminal fermentation of different diets and feedstuffs by sheep. Anim Feed Sci Technol 176:131–139 (2012). 10 AOAC, Official Methods of Analysis, 16th edition. Association of Official Analytical Chemists, Arlington, VA (1999). 11 Van Soest PJ, Limiting factors in plant residues of low biodegradability. Agric Environ 6:135–143 (1981). 12 Abijaoude JA, Morand-Fehr P, Tessier J, Schmidely PH and Sauvant D, Diet effect on the daily feeding behaviour, frequency and characteristics of meals in dairy goats. Livest Prod Sci 64:29–37 (2000). 13 Di Trana A, Celi P, Claps S, Fedele V and Rubino R, The effect of hot season and nutrition on the oxidative status and metabolic profile in dairy goats during mid lactation. Anim Sci 82:717–722 (2006). 14 Castillo C, Pereira V, Abuelo A and Hernández J, Effect of supplementation with antioxidants on the quality of bovine milk and meat production. Sci World J 2013:616098 (2013). 15 Dumay O, Costa J, Desjobert JM and Pergent G, Variations in the concentration of phenolic compounds in the seagrass Posidonia oceanica under conditions of competition. Phytochemistry 65:3211–3220 (2004). 16 Haznedaroglu MZ and Zeybek U, HPLC determination of chicoric acid in leaves of Posidonia oceanica. Pharmaceut Biol 45:745–748 (2007). 17 Heglmeier A and Zidorn C, Secondary metabolites of Posidonia oceanica (Posidoniaceae). Biochem Syst Ecol 38:964–970 (2010). 18 Hammami S, Salem AB, Ashour ML, Cheriaa J, Graziano G and Mighri Z, A novel methylated sesquiterpene from seagrass Posidonia oceanica (L.) Delile. Nat Prod Res 27:1265–1270 (2013). 19 Castillo C, Hernandez J, Pereira V and Benedito JL, Update about nutritional strategies in feedlot for preventing ruminal acidosis, in Advances in Zoology Research, Vol. 4, ed. by Jenkins OP. Nova Science Publishers, New York, NY, pp. 1–84 (2012). 20 Celi P, di Trana A and Claps S, Effects of plane of nutrition on oxidative stress in goats during the peripartum period. Vet J 184:95–99 (2010). 21 Gokce G and Haznedaroglu MZ, Evaluation of antidiabetic, antioxidant and vasoprotective effects of Posidonia oceanica extract. J Ethnopharmacol 115:122–130 (2008).
609
J Sci Food Agric 2016; 96: 602–609
© 2015 Society of Chemical Industry
wileyonlinelibrary.com/jsfa
