Effects of source and level of fish oil supplementation in late pregnancy on feed intake, colostrum production and lamb output of ewes

Effects of prenatal fish oil supplementation on the development and performance of female kids after weaning

This study was performed to determine the influence of fish oil, an omega-3 fatty acids source, supplemented to diets of goats throughout all stages of gestation on the growth and milk production of weaned female kids. Eighty German Fawn (75%) x Hair (25%) crossbred goats were randomly assigned to treatment (fish oil, FiO group) and control (Rumen protected fat, RPF group) groups during the first half of pregnancy. Subsequently, the FiO group was further allocated into FiO-FiO and FiO-RPF subgroups and RPF group was further divided into RPF-FiO and RPF-RPF subgroups containing 20 goats in each during the second half of pregnancy. The growth and feed intake of 41 female kids (aged 75.1 ± 6.73 days, with a mean live weight of 11.6 ± 3.00 kg) were recorded for a 98 day post-weaning, In the continuation of the study, live weight changes, milk yield and composition of young female goats from mating to the second month of lactation and the growth of female kids until weaning were studied for a total of 210 days. Maternal nutrition slightly influenced the live weight gain of female kids over a 98-day investigation period (p = 0.070). When growth performance was considered, a higher feed conversion efficiency of female offspring was determined in RPF-FiO (5.52) treatment group compare to female kids in other treatment groups (p = 0.086). However, the maternal feeding system significantly affected live weight in the RPF-FiO treatment group during the mating period (P = 0.054). Concerning the feed intake, maternal nutrition significantly affected the feed intake of female kids (p < 0.01) with the highest feed consumption in the FiO-RPF group. The findings of this study have shown that fish oil enriched diet given to goats during gestation improved daily live weight changes and total live weight gain of female kids despite the initial disadvantage after weaning. At mating time, the live weight of young female goats in the RPF-FiO treatment group, which exhibited the highest feed conversion ratio during the 98-day study, was higher than the remaining treatment groups. Maternal nutrition had no effect on milk yield or milk components in young goats during lactation. Young female goats born to dams in the FiO-RPF group showed better performance than the other groups regarding live weight performance of their offspring on 56th day postpartum.

Fish Oil Supplementation as an Omega-3 Fatty Acid Source during Gestation: Effects on the Performance of Awassi Ewes and Their Offspring

The primary aim of this research was to assess the impact of supplementing fish oil into the diet of pregnant Awassi ewes on various aspects of the dam's productive performance, offspring birth weight, colostrum yield and quality, milk production and composition, postpartum offspring performance, and the composition of fatty acids in milk. In this study, two different fat sources, namely palm oil (PO) and fish oil (FO), were utilized, with both being included at a rate of 2.4% of dietary dry matter (DM) during the initial 65 days of gestation (early gestation stage), and then at 2.1% DM from day 65 of gestation until lambing (late gestation stage). The study subjects were Awassi ewes with a body weight (BW) averaging 57 ± 1.5 kg and an age of 3.5 ± 1.2 years. These ewes were randomly assigned to one of four dietary treatments: (i) a diet containing only palm oil from day 0 to day 150 of pregnancy (PO, n = 15); (ii) a diet containing palm oil from day 0 to day 65 of pregnancy, followed by a diet containing fish oil from day 66 to day 150 of pregnancy (POFO, n = 16); (iii) a diet containing fish oil from day 0 to day 65 of pregnancy, followed by a diet containing palm oil from day 66 to day 150 of pregnancy (FOPO, n = 16); (iv) a diet containing only fish oil from day 0 to day 150 of pregnancy (FO, n = 16). Within each treatment, ewes were housed in three replicates, with each replicate further divided into three subgroups. The first two subgroups each contained eight ewes, while the third subgroup contained nine ewes. In addition, each treatment contained 10 primiparous and 15 multiparous ewes. The results indicated that the POFO treatment led to significant increases (p < 0.05) in birth weight, gestation length, and colostrum IgG concentration. However, it also resulted in a decrease (p < 0.001) in colostrum production and a reduction (p < 0.001) in the percentage of milk fat and milk protein. Furthermore, the milk from the POFO treatment exhibited higher levels of polyunsaturated fatty acids (PUFAs) (p < 0.001) compared to the PO and FOPO treatments, while the milk saturated fatty acids (SFA) were lower (p < 0.001). In conclusion, the addition of fish oil at a rate of 2.1% DM during the late pregnancy period showed promise for enhancing birth weight, colostrum IgG concentration, and the PUFA content in the milk.

The Effect of Supplementation Using a Mixture of Fish Oil and Linseed on the Level of Immunomodulatory Components in Bovine Colostrum

The aim of this study was to determine the effect of supplementing rations, with a mixture of fish oil and linseed, on the level of immunomodulatory components in colostrum. Twenty multiparous cows, that were three weeks before scheduled calving, had a body condition of 3-3.5, and had not been diagnosed with multiple pregnancies, were qualified for the experiment. The cows were divided into two groups: experimental (FOL) (n = 10) and control (CTL) (n = 10). The CTL group were individually given the standard food ration for dry cows for about 21 days before calving, while the FOL group received food rations that were enriched with 150 g of fish oil and 250 g of linseed (golden variety). Colostrum samples for testing were taken twice a day on the first and second days of lactation, and then once a day from the third to the fifth day of lactation. The experiment showed that the applied supplementation had an impact, in the form of increasing the fat, protein, IgG, IgA, IgM, vitamin A, C22:6 n-3 (DHA), and C18:2 cis9 trans11 (CLA) contents in colostrum; however, the C18: 2 n-6 (LA) and C20:4 n-6 (AA) contents decreased. Due to the lower quality of colostrum found in high-yield cows, and therefore in the Holstein-Friesian breed, it is possible to improve the quality by, among other things, introducing nutritional modifications during the second stage of the dry period.

Influence of flaxseed with rumen undegradable protein level on milk yield, milk fatty acids and blood metabolites in transition ewes

An experiment was conducted to determine the effects of two levels of rumen undegradable protein (RUP) without or with whole or extruded flaxseed on milk yield, milk component, milk fatty acids (FAs) profile and plasma metabolites in transition ewes. Three weeks before and after lambing, seventy-two Baluchi ewes were used in a completely randomized design with a 3 × 2 factorial arrangement of treatments. The treatments contained 1) no flaxseed + 20% RUP (no flaxseed, low RUP [NFLR]); 2) no flaxseed + 40% RUP (no flaxseed, high RUP [NFHR]); 3) 10% whole flaxseed + 20% RUP (whole flaxseed, low RUP [WFLR]); 4) 10% whole flaxseed + 40% RUP (whole flaxseed, high RUP [WFHR]); 5) 10% extruded flaxseed + 20% RUP (extruded flaxseed, low RUP [EFLR]), and 6) 10% extruded flaxseed + 40% RUP (extruded flaxseed, high RUP [EFHR]). Ewes fed 10% extruded flaxseed exhibited higher (p < 0.001) dry matter intake (DMI) and colostrum yield (p < 0.1) compared to other treatments. Two types of flaxseed and RUP levels had no significant effect on milk yield, but milk fat and protein contents decreased and increased in diets containing 40% RUP, respectively. Ewes fed extruded flaxseed produced milk with lower concentrations of saturated fatty acids (SFA) and higher α-linolenic and linoleic acids and also polyunsaturated fatty acids (PUFA) compared to other groups (p < 0.05). During post-lambing, the ewes fed diets containing flaxseed exhibited higher concentration of serum non-esterified FAs (NEFA) compared to diets without flaxseed (p < 0.01). The concentration of serum β-hydroxybutyric acid (BHBA) decreased in the diets containing flaxseed types at pre-lambing, but increased in diets containing extruded flaxseed at post-lambing (p < 0.01). The serum glucose concentration of ewes (pre and post-lambing) which consumed diets containing extruded flaxseed or 40% RUP increased, but blood urea concentration was elevated following supplementation of diet with whole flaxseed or 40% RUP (p < 0.001). In conclusion, utilization of 10% extruded flaxseed in the diets of transition ewes had positive effects on animal performance with favorable changes in milk FAs profile. However, there is no considerable advantage to supply more than 20% RUP level in the diet of transition dairy sheep.

Maternal supplementation with fish oil modulates inflammation-related MicroRNAs and genes in suckling lambs

Dietary n-3 long-chain fatty acids (n-3 LCFA) have been shown to modify lipid metabolism and immune function. The objective of this study was to evaluate the effect of periparturient fish oil (FO) supplementation on the inflammation and metabolic health of ewes and their lambs at a molecular level. Prepartum ewes were fed control diet (CON, n = 12) or CON supplemented with 2% DM of calcium soap of FO (n = 12) from 28 days before until 21 days after parturition. The ewes were evaluated for plasma metabolites and milk composition. The experiment was followed by analyzing the relative transcript abundance of circulating microRNAs (miRNAs) in plasma and targeted miRNA/mRNA expression in peripheral blood mononuclear cells (PBMCs) in both ewes and lambs. FO treatment decreased prepartum feed intake (1812 ± 35 vs 1674 ± 33 g/day, P < 0.01), whereas the influence on plasma metabolites was negligible. Dietary FO supplementation decreased milk fat percentage (8.82 ± 0.49 vs 7.03 ± 0.45, P = 0.02) and reduced milk n-6/n-3 (P < 0.05). Also, it altered the expression of plasma-circulating miRNAs in both ewe and lamb (P < 0.05). Furthermore, maternal nutrition of FO downregulated the relative expression of miR-33a and miR-146b and transcript abundance of genes IL-1β (0.41-fold) and NF-κB (0.25-fold) in lambs' PBMC. In conclusion, results showed that FO supplementation starting antepartum affects milk composition and circulating miRNA in dams and the inflammatory markers in lambs delivered by the supplemented ewes. These may provide a strategy to maintain immune balance during gestation and develop the immune system in lambs.

Effects of replacing grass silage with either maize silage or concentrates during late pregnancy on the performance of breeding ewes fed isonitrogenous diets

A study was undertaken to investigate the performance of breeding ewes fed a range of forage and concentrate-based diets in late pregnancy, balanced for supply of metabolizable protein (MP). For the final 6 weeks before lambing, 104 twin-bearing multiparous ewes were offered one of four diets: ad libitum precision-chop grass silage + 0.55 kg/day concentrates (GS); ad libitum maize silage + 0.55 kg/day concentrates (MS); a 1 : 1 mixture (on a dry matter (DM) basis) of grass silage and maize silage fed ad libitum + 0.55 kg/day (GSMS); or 1.55 kg/day concentrates + 50 g/day chopped barley straw (C). The CP content of the concentrates was varied between treatments (157 to 296 g/kg DM) with the aim of achieving a daily intake of 130 g/day MP across all treatments. Compared with ewes fed GS, forage DM intake was higher (P < 0.05) in ewes fed MS (+0.21 kg/day) and GSMS (+0.16 kg/day), resulting in higher (P < 0.001) total DM intakes with these treatments. C ewes had the lowest total DM intake of all the treatments examined (P < 0.001). C ewes lost more live weight (LW; P < 0.001) and body condition score (BCS; P < 0.05) during the first 3 weeks of the study but there were no dietary effects on ewe LW or BCS thereafter. The incidence of dystocia was lower (P < 0.01) in C ewes compared with those offered silage-based diets (7.5% v. 37.4% ewes), and was higher (P < 0.01) in ewes fed MS compared with GS or GSMS (50.7%, 34.7% and 26.9%, respectively). There were no significant dietary effects on the plasma metabolite concentrations of ewes in late pregnancy, pre-weaning lamb mortality, weaned lamb output per ewe or on lamb growth rate. The results of this study demonstrate that both maize silage and all-concentrate diets can replace grass silage in pregnant ewe rations without impacting on performance, provided the supply of MP is non-limiting. The higher incidence of dystocia in ewes fed maize silage as the sole forage is a concern.