Author : Prasetyo Nugroho

Summary : Ettawa-grade (Peranakan Etawah/PE) goat is well known as one of Indonesia's germplasm that has a function and a strategic role in humans' life as meat and dairy producers. However, the low body condition score (BCS) during mating could reduce reproductive efficiency. Flushing with fat supplementation is a strategy to raise the nutritional status of the female animal to improve reproductive efficiency in humid tropics regions. Besides increasing energy density with fat supplementation in the ration, differences in the composition of the fatty acid contents, particularly polyunsaturated fatty acids (PUFAs) have various metabolic effects and having an essential role in determining the reproductive performance. Therefore, further study is needed by comparing the effect of PUFAs both linolenic and linoleic in improving reproductive performance and productivity of Ettawa­grade goats.

The experiment was designed to evaluate and analyze the influence of flushing rations supplemented with different types of fatty acids (lauric, linoleic, and a­linolenic acid) in Ettawa-grade does on (i) growth and development of follicles during estrus; (ii) reproductive performance; (iii) lactation performance; and (iv) pre-weaning growth, development, and survival of their off springs. The experiment was performed from March 2018 to February 2019 at the Field and Analysis Laboratory of Meat and Draught Animal Nutrition, Laboratory of Dairy Nutrition, IPB University, Bogor, and Laboratory of Integrated Research, Faculty of Veterinary Medicine, University of Syiah Kuala, Banda Aceh. Ethical clearance was approved by the Animal Care and Use Committee, the Institute of Research and Community Empowerment of IPB (LPPM-IPB), with the number 119-2018 IPB.

The first study was aimed at evaluating and analyzing the stimulation of follicle growth and development during estrus and its correlations with estradiol and progesterone concentrations in Ettawa-grade does fed a flushing ration with different types of fatty acids. This study used 9 Ettawa-grade does in the second parity with the average body weight of 32.11 ± 2.19 kg that were divided into three groups of flushing supplement i.e., (i) ration supplemented with 2.8% lauric acid from coconut oil as a control without PUFA (T1); (ii) ration supplemented with 2.8% linoleic acid from sunflower oil (T2); and (iii) ration supplemented with 2.8% a-linolenic acid from flaxseed oil (T3). The rations were formulated isocaloric (total digestible nutrient (TDN) = 77%) and isonitrogenous (crude protein (CP) = 15%). The flushing supplement was given for 21 days starting from three days after estrus synchronization without mated until the appearance of the next phase of estrus cycle after the flushing. A completely randomized design (CRD) was used as the experimental design in this study. The BCS, plasma glucose concentration, and plasma cholesterol concentration data generated from repeated samples were analyzed by repeated measurement analysis of variance (ANOVA). Data on nutrient consumption, the number and diameters of follicles, the diameters of corpus luteum, plasma estradiol concentration, and plasma progesterone concentrations were analyzed using CRD ANOVA followed by the Duncan Multiple Range Test. The correlations between the total number of follicles and plasma estradiol concentration and between the diameter of corpus luteum and plasma progesterone concentration were analyzed using correlation analysis. The results indicated that treatment with different types of fatty acid in the flushing ration did not affect the nutrient consumption; BCS; and plasma glucose, cholesterol, and progesterone concentrations among treatments. However, flushing for 3 weeks increased BCS by 0.8-0.9 and plasma cholesterol concentrations by 23.12-50.12 mg/dL compared to those before flushing. The total number of large follicles was significantly highest in does treated with 2.8% a-linolenic acid (T3). However, supplementation of 2.8% lauric acid (T1) dramatically increased plasma estradiol concentrations during estrus. Plasma concentrations of progesterone in all groups of experimental does were similar during the estrus period after flushing treatment. There was a strong correlation (r = 0.63) between the total number of follicles and plasma estradiol concentrations in the overall does and moderate correlation (r = 0.55) between the diameter of corpus luteum and plasma progesterone concentrations in the overall does. In conclusion on the first study, flushing with supplementation of 2.8% a-linolenic acid from flaxseed oil in the ration increased the number of large-size preovulatory follicles. A strong association between the total number of follicles and plasma estradiol concentration and a moderate association between the diameter of corpus luteum and concentrations of plasma progesterone were found in the overall does.

The second study was aimed to evaluate and analyze the effect of flushing ration contains fat sources differing in fatty acid profile lauric, linoleic, and linolenic acids) on reproductive performance in Etawa-grade does. Eighteen Ettawa-grade does in the second parity with the average body weight of 34.28 ± 3.38 kg and initial BCS of 1.92 ± 0.26 were divided into three groups (n = 6 per groups). The flushing rations were formulated in isocaloric and composition and supplemented with different types of fatty acids i.e., each respective ration contained 2.8% of !auric acid (Tl) sourced from coconut oil, linoleic acid (T2) sourced from sunflower oil, or a-linolenic acid (T3) sourced from flaxseed oil. Flushing period was started from 3 weeks pre-mating to 2 weeks post-mating and 4th month gestation until partus. Estrus was synchronized by injecting prostaglandin F2a two times at 11 days interval and mated naturally. The experiment used a completely randomized design. The results showed no treatment effect on nutrient consumption, glucose, and cholesterol concentrations. At 2 days after estrus synchronization, estradiol concentration was lower (P < 0.05) in T3 and T2 groups than Tl group, whereas progesterone concentration was higher (P < 0.05) in T3 group than Tl and T2 groups. At 19 weeks gestation, progesterone concentration was higher in T3 group and T2 than Tl groups. The number and viability of embryos, kidding rate, and total number of kids were higher in T3 group than in Tl and T2 groups. The different fatty acids in the ration affected sex ratio of their offsprings. Tl and T3 groups markedly dominated to have male kids, while T2 dominated by female kids. Even though the litter size was similar (P > 0.05) in all treatments, the Tl group increased the twin kids ratio compared to the other treatments. In conclusion on the second study, flushing with supplementation of 2.8% a-linolenic acid in the ration improved reproductive performance through increasing the synthesis of the progesterone hormone, the number and viability of embryos, kidding rate, twinning rate, total number of kids, and male born sex ratio.

The third study was aimed to evaluate and analyze the influence· of flushing rations containing various types of fatty acids in late pregnancy and early lactation on lactation performance of Etawa-grade does and pre-weaning growth, development, and survival of their off springs. A total of 16 pregnant Ettawa-grade does with a gestational age of 16 weeks with the average body weight of 42.74 ± 3.72 kg were divided into three groups. Experimental does were fed flushing ration containing different types of fatty acids. Dietary groups were: (i) ration supplemented with 2.8% lauric acid from coconut oil (Tl, n = 5); (ii) ration supplemented with 2.8% linoleic acid from sunflower oil (T2, n = 5); and (iii) ration supplemented with 2.8% a-linolenic acid from flaxseed oil (T3, n = 6). The flushing period started from 16th-week pregnancy until 2 weeks after partus, after that the does had a lactation diet. Kids performance was evaluated until kids were weaned at 8 weeks of age. The variables measured for observations of lactation performance were nutrient consumption, BCS, blood urea nitrogen, glucose and cholesterol concentrations, blood hematology profile, the percentage of body weight loss, udder volume, composition of colostrum and milk, milk yield, fatty acids profile in milk. The variables measured for observations of kid performance were birth weight, neonatal behavior, concentration of igG in colostrum and plasma of does and kids, mortality and kids survival. The data were analyzed using one way ANOVA, except blood hematology profile, mortality and kids survival. A factorial randomized complete design 3 x 2 in which the first factor was fatty acids and the second factor was litter sizes (LSI and LS2) was used to measure blood hematology. In addition, data on the kids mortality and kids survival rates were analyzed descriptively.

The findings of the third study on lactation performance showed that nutrient consumption, BCS, the percentage of body weight loss, glucose blood urea nitrogen, cholesterol concentration, composition of colostrum and milk were similar (P > 0.05) among all groups. The udder volume and average daily milk yield were higher (P < 0.05) in T3 group and T2 than Tl groups. Milk proportions of omega-3 fatty acids increased, whereas omega-6/omega-3 ratio decreased in T3 group as compared with the other groups. Leukocyte level was higher in LS2 compared to LS 1 (P < 0.05), but it was not affected by fatty acids. Even though the lymphocyte level was the highest in T3 group and LS2 (P<0.05), it was still in the normal range. Monocyte and neutrophil were lower in T3 group compared to Tl group (P < 0.05), but it was similar to T2 group.

The results on lactation performance showed that in twin kids, the fastest first­time successful standing and suckling normally was observed in T3 group, while in single kids there was no significant difference. Immunoglobulin G (IgG) level in colostrum, kids plasma both single and twin were not influenced by the treatments, while lgG level in the plasma of does was significantly the highest in T3 group. There was no mortality in kids born from does treated with T2 and T3, while mortality rate in kids born from does treated with coconut oil was around 16.67%. The birth weight of twin kids born from does treated with T3 was significantly higher (P < 0.05) than twin kids born from does treated with Tl, but similar with twin kid born from does treated with T2. Meanwhile, birth weight of single kid was similar in all groups. The highest birth weight of twin kid born from does treated with T3 had an impact on body weight of 2 weeks old, and the body weight of weaning, as well as average daily gain until weaning. In conclusion on the lactation performance, a-linolenic acid supplementation at 2.8% of total ration during the flushing period increased udder volume, average daily milk yield, milk proportions of omega-3 fatty acids, and decreased the ratio of ornega-6 to omega-3 fatty acids in milk of Etawah-grade does. On their offspring performance, maternal a-linolenic acid supplementation during the flushing period decreased latency of successful standing and suckling and increased birth and weaning weights on twin kids.

In conclusion, flushing with supplementation of 2.8% a-linolenic acid from flaxseed oil in the ration improved reproductive performance in Etawah-grade does through increasing the synthesis of the progesterone hormone, the number of large­size preovulatory follicles, the number and viability of embryos, kidding rate, twinning rate, total number of kids, and male born sex ratio. In addition, a-linolenic acid supplementation at 2.8% of total ration in flushing period promoted lactation performance of does through increasing udder volume, and average daily milk yield, and milk proportions of omega-3 fatty acids. Maternal supply of omega-3 improved their twin offspring performance through decreasing latency of successful standing and suckling and an average daily gain that supports higher body weight at weaning time.