Effect of different feeding regimes on pre-weaning growth rumen fermentation and its influence on post-weaning performance of lambs

Ruminal microbial metagenomes and host transcriptomes shed light on individual variability in the growth rate of lambs before weaning: the regulated mechanism and potential long-term effect on the host

Weaning weight is a reflection of management during the breastfeeding phase and will influence animal performance in subsequent phases, considered important indicators within production systems. The aims of this study were as follows: (i) to investigate variability in the growth rate among individual lambs from ewes rearing single or twin lambs fed with two different diets and (ii) to explore the molecular mechanisms regulating the growth rate and the potential long-term effects on the host. No significant change in lamb average daily gain (ADG) was observed in litter size and diet treatment, and there were large variations among individual lambs (ranging from 0.13 to 0.41 kg/day). Further analysis was conducted on serum amino acids, rumen fermentation characteristics, rumen metagenomics and transcriptome, and hepatic transcriptome of lambs with extremely high (HA; n = 6) and low (LA; n = 6) ADG. We observed significant increases in serum lysine, leucine, alanine, and phenylalanine in the HA group. The metagenome revealed that the HA group presented a higher rumen propionate molar proportion via increasing gene abundance in the succinate pathway for propionate synthesis. For the rumen transcriptome, higher expressed gene sets in the HA group were mainly related to rumen epithelial growth, including cytokine-cytokine receptor interaction, Jak-STAT signaling pathway, and adherens junction. For the liver transcriptome, the upregulated KEGG pathways in the HA group were primarily associated with fatty acid degradation, glyoxylate and dicarboxylate metabolism, cholesterol metabolism, and the immune system. This research suggests that preweaning lambs with high ADG may benefit from rumen development and enhanced liver metabolic and immune function.

IMPORTANCE

There is accumulating evidence indicating that the early-life rumen microbiome plays vital roles in rumen development and microbial fermentation, which subsequently affects the growth of young ruminants. The liver is also vital to regulate the metabolism and distribution of nutrients. Our results demonstrate that lambs with high average daily gain (ADG) enhanced microbial volatile fatty acid (VFA) metabolism toward rumen propionate and serum amino acid (AA) production to support host growth. The study highlights that high ADG in the preweaning period is beneficial for the rumen development and liver energy metabolism, leading to better growth later in life. Overall, this study explores the molecular mechanisms regulating the growth rate and the potential long-term effects of increased growth rate on the host metabolism, providing fundamental knowledge about nutrient manipulation in pre-weaning.

Effect of supplementation of roasted oilseeds and phytochemical-rich herbages on nutrient utilization, methane emission, and growth performance in finisher lambs

Ruminal methanogenesis is a major contributor to global environmental pollution in the agriculture sector. Dietary intervention modestly abates enteric methane emissions in ruminants. Therefore, the present experiment was conducted to evaluate the combined effect of dietary oilseeds and phytochemical-rich herbages on enteric methane emission, growth performance, and nutrient utilization in lambs. Forty-eight finisher Malpura lambs were divided into 4 groups (RSZ, RSP, RSLZ, and RSLP) of 12 each in a factorial design. Lambs were fed ad libitum concentrate formulated with roasted soybean (RS) or roasted soybean plus linseed (RSL) along with Ziziphus nummularia (Z) or Prosopis cineraria (P) leaves as roughage sources. Variation in the source of roughage significantly affected feed intake, and it was higher (P < 0.05) in lambs fed Prosopis cineraria leaves (RSP and RSLP). The average daily gain was improved (P < 0.05) by 28.6 and 25.0% in lambs fed Prosopis cineraria, i.e., RSP and RSLP respectively, than those fed Ziziphus nummularia leaves irrespective of concentrate diets. Overall, microbial nitrogen synthesis (MNS) was higher (P < 0.05) in lambs fed roasted soybean (RS) than roasted soybean plus linseed (RSL); however, combination of Prosopis cineraria with both the concentrate diets increased MNS, than the combination of roasted oilseeds and Ziziphus nummularia. No significant interaction was observed in the concentration and proportion of volatile fatty acids by feeding combination of roasted oilseed and tree leaves; however, the proportion of acetic and propionic acid was higher (P < 0.05) in the RSL group compared to RS. Methane emission per kg dry matter intake was reduced (P < 0.05) by feeding Prosopis cineraria leaves regardless of concentrate mixture. As a result, the loss of metabolizable energy through methane emission was lowered by 0.7 and 4.6% when Prosopis cineraria leaves were combined with roasted soybean (RSP) and roasted soybean plus linseed (RSLP), respectively. From the present findings, it can be concluded that combination of Prosopis cineraria leaves either with roasted soybean or roasted soybean plus linseed reduced enteric methane emissions more effectively than Ziziphus nummularia leaves, and the energy saved was transformed into higher body weight gain and improved feed conversion ratio.

Effects of Two Feeding Patterns on Growth Performance, Rumen Fermentation Parameters, and Bacterial Community Composition in Yak Calves

The health of young ruminants is highly dependent on early rumen microbial colonization. In this study, the effects of milk replacer on growth performance, rumen fermentation, and the rumen microflora in yak calves were evaluated. Sixty yak calves (body weight = 22.5 ± 0.95 kg, age = 30 ± 1 d) were assigned to the CON group (breastfed) or TRT group (milk replacer fed) and evaluated over 120 d. At 120 d, ruminal fluid samples were collected from 14 calves and then conducted for rumen fermentation and microbiota analyses. There was no difference in growth performance; however, calf survival was higher in the TRT group than in the CON group. The concentration of total volatile fatty acids and the molar proportion of butyric acid and lactic acid were increased with milk replacer feed in the TRT group (p < 0.05), but iso-valeric acid concentration was highest in the CON group (p < 0.05). Firmicutes and Bacteroidetes were the most dominant phyla in the CON and TRT groups, respectively. In the TRT group, Bacteroidetes, Prevotellaceae, Bacteroidia, Bacteroidetes, and Prevotella_1 were the dominant flora in the rumen of calves. The relative abundances of various taxa were correlated with rumen fermentation parameters; the relative abundance of Quinella and iso-butyrate levels were positively correlated (r = 0.57). The relative abundances of the Christensenellaceae_R-7_group and A/P were positively correlated (r = 0.57). In summary, milk replacer is conducive to the development of the rumen microflora, the establishment of rumen fermentation function, and the implementation of early weaning in yaks.

Effects of Bacillus licheniformis and Combination of Probiotics and Enzymes as Supplements on Growth Performance and Serum Parameters in Early-Weaned Grazing Yak Calves

Early weaning is an effective strategy to improve cow feed utilization and shorten postpartum intervals in cows; however, this may lead to poor performance of the weaned calves. This study was conducted to test the effects of supplementing milk replacer with Bacillus licheniformis and a complex of probiotics and enzyme preparations on body weight (BW), size, and serum biochemical parameters and hormones in early-weaned grazing yak calves. Thirty two-month-old male grazing yaks (38.89 ± 1.45 kg body weight) were fed milk replacer at 3% of their BW and were randomly assigned to three treatments (n = 10, each): T1 (supplementation with 0.15 g/kg Bacillus licheniformis), T2 (supplementation with a 2.4 g/kg combination of probiotics and enzymes), and a control (without supplementation). Compared to the controls, the average daily gain (ADG) from 0 to 60 d was significantly higher in calves administered the T1 and T2 treatments, and that from 30 to 60 d was significantly higher in calves administered the T2 treatment. The ADG from 0 to 60 d was significantly higher in the T2- than in the T1-treated yaks. The concentration of serum growth hormone, insulin growth factor-1, and epidermal growth factor was significantly higher in the T2-treated calves than in the controls. The concentration of serum cortisol was significantly lower in the T1 treatment than in the controls. We concluded that supplementation with probiotics alone or a combination of probiotics and enzymes can improve the ADG of early-weaned grazing yak calves. Supplementation with the combination of probiotics and enzymes had a stronger positive effect on growth and serum hormone levels, compared to the single-probiotic treatment with Bacillus licheniformis, providing a basis for the application of a combination of probiotics and enzymes.

Effects of milk replacer feeding level on growth performance, rumen development and the ruminal bacterial community in lambs

Feeding with a suitable level of milk replacer (MR) can improve the survival rate and stimulate the growth potential of early lambs. However, feeding excessive MR might be detrimental to rumen development and microbial colonization. Herein, we investigated the effects of feeding different levels of MR on rumen digestive function and ruminal microorganisms. Fourteen healthy male Hu lambs with similar birth weights and detailed pedigree records were divided into two groups to receive low (2% of average body weight per day) and high (4% of average body weight per day) levels of MR. We analyzed the effects of the MR feeding level on growth performance, fiber degradation rates, rumen fermentation parameters, enzyme activities and rumen histomorphology. We found that feeding with a high level of MR improved the average daily gain of early lambs, but decreased the starter intake, rumen weight and papillae length. We also analyzed the effects of the MR feeding level on the rumen microbiota using 16S-rRNA amplicon sequencing data. The results showed that high a MR feeding level increased the rumen microbial diversity but decreased the abundance of many carbohydrate degrading bacteria. Several bacterial genera with significant differences correlated positively with rumen cellulase activity and the acid detergent fiber degradation rate. Our results suggested that a high level of MR could improve the growth performance of early lambs in the short term; however, in the long term, it would be detrimental to rumen development and have adverse effects on the adaptation process of the microbiota to solid feed.

Early feeding strategies in lambs affect rumen development and growth performance, with advantages persisting for two weeks after the transition to fattening diets

This study aimed to explore the effects of early feeding strategies on the growth and rumen development of lambs from pre-weaning to the transition to fattening diets. Ninety-six newborn, male lambs with similar body weights were randomly assigned to three treatments: fed starter at 42 days old + weaned at 56 days old (Ctrl, n = 36), fed starter at 7 days old + weaned at 56 days old (ES, n = 36), and fed starter at 7 days old + weaned at 28 days old (ES + EW, n = 24). The fattening diets of all lambs were gradually replaced from 60 to 70 days of age. Six randomly selected lambs from each treatment were slaughtered at 14, 28, 42, 56, 70, and 84 days of age. The results showed that the richness and diversity of rumen microbiota of lambs in the Ctrl group were distinct from those of lambs in the other groups at 42 days of age. Moreover, transcriptome analysis revealed 407, 219, and 1,211 unique differentially expressed genes (DEGs) in the rumen tissue of ES vs. Ctrl, ES vs. ES + EW, and ES + EW vs. Ctrl groups, respectively, at 42 days of age. Different early feeding strategies resulted in differences in ruminal anatomy, morphology, and fermentation in lambs from 42 to 84 days of age (P < 0.05). Lambs in the ES + EW group had a higher average starter diet intake than those in the other groups (P < 0.05) from 28 to 56 days of age, which affected their growth performance. After 42 days of age, the body and carcass weights of lambs in the ES and ES + EW groups were higher than those in the Ctrl group (P < 0.05). These findings demonstrate that feeding lambs with a starter diet at 7 days of age and weaning them at 28 days of age can promote rumen development and improve growth performance, and this advantage persists for up to 2 weeks after transition to the fattening diet.

Effect of Marine Red Yeast Rhodosporidium paludigenum on Diarrhea Rate, Serum Antioxidant Competence, Intestinal Immune Capacity, and Microflora Structure in Early-Weaned Lambs

In this study, the influences of marine red yeast Rhodosporidium paludigenum (MRYP) on diarrhea rate, serum antioxidant capacity, intestinal immunity capacity, and microflora structure of early-weaned lamb were investigated in a 60-day feeding trial. A total of 96 early-weaned lambs were utilized in this study. The lambs were divided into four experimental groups based on the percentage of marine red yeast Rhodosporidium paludigenum (MRYP) as milk replacer supplement. The rates of milk replacer supplement for the four groups were 0, 0.1%, 0.3%, and 0.5% of marine red yeast Rhodosporidium paludigenum (MRYP), respectively. The study was continued for 30 days. The results showed that (1) compared with control group, 0.5% marine red yeast Rhodosporidium paludigenum (MRYP) supplementation caused significantly decreases in average fecal score and diarrhea frequency by 33.74% and 40.23% (P < 0.05). (2) No significant difference was found in all tested related antioxidant indexes in serum of four treatments (P > 0.05). (3) The concentrations of SIgA, IgG, and IL-10 of group IV was significantly increased by 17.78%, 18.27%, and 8.17%, but the IL-6 and TNF-α were significantly decreased by 21.20% and 31.80%, compared to group I in the colon (P < 0.05). (4) The number of Bifidobacterial and Lactobacilli of group IV was significantly increased by 14.87% and 15.09%, but Escherichia coli and Salmonella were significantly decreased by 20.19% and 10.15%, compared to group I in the colon (P < 0.05). (5) A portion of marine red yeast Rhodosporidium paludigenum (MRYP) survived in the intestine of early-weaned lamb, and the number of survival marine red yeast Rhodosporidium paludigenum (MRYP) increased as the addition of marine red yeast Rhodosporidium paludigenum (MRYP) increased from 0.1 to 0.5% in milk replacer. Therefore, marine red yeast Rhodosporidium paludigenum (MRYP) has a potential to be a replacer of antibiotics for prevention and treatment of diarrhea in early-weaned lambs.

Growth and Body Composition of Artificially-Reared Lambs Exposed to Three Different Rearing Regimens

Simple Summary

Optimum lamb growth and cost-effective artificial lamb rearing are important to maximise farm profit. In addition to milk feeding, supplementation of a solid feed with balanced nutrients and an adequate level of fibre will aid rumen development, allowing for a smooth transition from a liquid to a solely solid diet. This study aimed to determine the effect of pellet fibre level, milk replacer composition and early milk weaning at 42 days of age, on the growth and body composition of lambs reared artificially to 57 days of age. Results demonstrate that lamb growth rate to 57 days of age was not affected by early weaning or pellet fibre level. Early milk weaning increased pellet intake and empty rumen weight. Early weaning resulted in leaner carcasses due to reduced fat deposition and lower total feed costs compared to lambs offered milk to 57 days of age. Overall, feeding lambs either low or high fibre pellets and weaning early (42 days of age) was shown to be beneficial, as growth was similar to unweaned lambs, but leaner carcasses and reduced feed costs were observed.

Abstract

This study was designed to investigate the influence of pellet fibre level, milk replacer composition and age at weaning on growth and body composition of lambs reared artificially. Romney ram lambs were randomly allocated to one of three rearing treatments; HFP57: commercial milk replacer to 57 days of age, and high fibre concentrate pellets; HFP42: commercial milk replacer with early weaning at 42 days of age, and high fibre concentrate pellets; LFP42: high protein milk replacer from 2–16 days of age followed by commercial milk replacer with early weaning at 42 days of age, and low fibre concentrate pellets. Lambs were slaughtered at 57 days of age. Overall average daily liveweight gain of lambs did not differ (p > 0.05) between treatments. Dressing out percentage, carcass weight, empty small intestine and omental fat were higher (p < 0.05) in HFP57 than in both HFP42 and LFP42 lambs. HFP42 and LFP42 lambs had heavier (p < 0.05) empty rumen weights. Whole body protein content was higher (p < 0.05) in HFP42 lambs compared to both HFP57 and LFP42 lambs. Fat content and daily fat deposition were greater (p < 0.05) in HFP57 lambs than HFP42 and LFP42 lambs. Weaning lambs at 42 days of age with provision of either low or high fibre concentrate pellets, resulted in similar growth rates, reduced whole body fat deposition and was a more cost-effective rearing regimen.

Nutrient intake, growth performance and nutrient digestibility of pre- and post-weaning Dorper lambs fed varying crude protein level

The objective of the present study was to investigate the effect of varying crude protein (CP) levels on intake, growth performances and nutrient digestibility of Dorper lambs at pre- and post-weaning period. Twenty lambs at 7 days old with an initial body weight of 2.91 kg were individually penned and randomly assigned into four (4) dietary groups using a randomised complete block design. In Trial I, pre-weaning lambs were fed with creep feeding (CF) diet containing 14% crude protein (CP) as a control diet (CON14), 16% (CF16), 18% (CF18) and 20% (CF20) of CP for 84 days. Following Trial 1, the animals were fed with a growing ration (GR) diet for 96-day feeding trial. The diets consisted of 11% CP as a control diet (CON11), 14% (GR14), 16% (GR16) and 18% (GR18) of CP. The water was available ad libitum and the feed intake was measured daily by the difference of feed offered and refused. The increase of CP level resulted in a linear increase of dry matter intake (DMI), nutrient intake and average daily gain (ADG) in pre- and post-weaning lambs. The DMI (g/day) of lambs fed with CF20 (1059.92) was significantly higher (p < 0.05) than CON14 (605.30), but it did not differ significantly with CF16 (866.80) and CF18 (680.40). Besides, the DMI (g/day) of lambs fed GR18 was found significantly higher than CON11 and GR16. In pre- and post-weaning lambs, there was a quadratic effect of increased CP level on the ADG. The ADG (g/day) of pre-weaning lambs fed with CF18 (247.86) and CF20 (251.28) were not significantly different (p > 0.05) compared to those fed with CF16 (217.95). For post-weaning lambs, GR16 had significantly higher ADG than CON11 (43.14), but it was no difference with GR14 (72.94) and GR18 (69.41). However, increased CP level resulted in linear increase of DM, ash, organic matter (OM) and CP digestibility. The present finding suggested that the optimum CP level for pre- and post-weaning Dorper lambs in Malaysia was 16% and 14%, respectively.

Milk replacer supplementation in early life optimizes the development of intestinal microbes in goats

Colonization and development of the gut microbiome during early life is important in establishing a host-microbial symbiotic relationship. It contributes to maintaining health and well-being throughout the life span. To date, early longitudinal development of intestinal microflora in the ileum micro-ecology of the Yimeng black goats (YBGs) is rare. The purpose of this research was to study the effect of milk replacer with age on the ileal microbiota growth and maturation in YBGs throughout the post-weaning phase. The newborn YBGs (n = 24) were divided into two groups, i.e., milk replacer (R group) and control group (B group). The microbiome of Ileum was observed on days 15, 25, 45, and 75. When compared with baseline (B group), the R group's alpha diversity was lower (day 15, 25, 45), but it gradually approached and exceeded the baseline in the later stages (day 75). On the time axis, the richness of intestinal microflora was increased with age, but there was no statistically significant difference. The relative abundances of Proteobacteria, Firmicutes, Peptoclustridium, Lachnospiraceae, and Prevotellaceae showed a continuous trend of increase initially. They then decreased except Ruminococcaceae, which reflected the gradual maturity of intestinal microbial development. Milk replacer treatment temporarily increased the abundance of Actinomycetes (day 25 and 45), while the relative proportion of several intestinal bacteria such as Parasutterella, Megasphaera, Prevotellaceae, Akkermansia, and Subdoligranulum species were significantly higher in R group than in B group. The major changes in gut microflora composition might reflect positive effect of milk replacer on the development and maturation of the intestine during the early stage, connecting with substrate availability in the gut. Our study provides an effective strategy to promote the development of the gut microbiome, which is helpful for a smooth transition during the early-weaning period in YBGs.

Growth performance, rumen fermentation and economic analysis of Malpura lambs raised on milk replacer at different weaning age under semiarid conditions

Pre-weaning nutrition has significant influence on post-weaning performance of lambs. Strategic weaning management on milk replacer allowance at this phase can be a promising approach for harvesting desired carcass trait in finisher phase. Therefore, present experiment aimed economizing pre-weaning weight gain in lambs by feeding milk replacer and subsequently minimizing weaning age. A study of 90 days duration was conducted to determine the production performance, nutrient utilization and rumen fermentation of lambs on milk replacer allowance at different weaning age. Sixty-six Malpura lambs (10 days of age) were randomly divided into 3 equal groups. Lambs in control group were allowed conventional free suckling of dam up to 90 day of age, whereas lambs in the two treatment groups, that is W60 and W90 were offered milk replacer and weaned at 60 and 90 days, respectively. Lambs in all groups were offered ad-libitum creep mixture, Ziziphus nummularia leaves, Vigna unguiculata hay and fresh Ailanthus excelsa leaves. Overall weight gain was 12.7 per cent higher (p < 0.05) in W90 than control whereas in W60 group it was statistically comparable with both control and W90 groups. Overall average daily gain was 12.1 per cent higher (p < 0.05) in W90 group as compared to control. In case of nutrient digestibility, there was significant depression of dry matter (DM), organic matter (OM), crude protein (CP) and neutral detergent fibre (NDF) by 16.9, 17.2, 9.3 and 32.0 per cent in W60 than control; however, in W90, CP digestibility was higher (p < 0.05) than control and W60. Considering economic analysis, the net return obtained from W90 (90 days weaning plus milk replacer allowance) was more 20.0 per cent higher than control. Therefore, it can be concluded that lamb rearing on milk replacer and weaning at 90 days have a sustained positive effect on lambs' production performance and is more profitable than the practice of milk replacer allowance and early weaning in semiarid conditions.

Microbiome analysis reveals gut microbiota alteration of early-weaned Yimeng black goats with the effect of milk replacer and age

Background

Colonization of intestinal microbiota in ruminant during the early life is important to host health, metabolism and immunity. Accumulating evidence revealed the ameliorative effect of milk replacer administration in the gut microbial development of early-weaned ruminants. Yimeng black goats (YBGs) inhabiting Shandong, China show a complex intestinal microbial ecosystem, but studies of their gut microbiota are still insufficient to report. Here, this study was performed to investigate how the gut microbiota develops in weaned YBGs with the effect of age and milk replacer.

Results

Results indicated that both age and milk replacer were important factors to change the gut microbiota of YBGs. Although the alpha diversity of gut microbiota did not change with the age of YBGs, the taxonomic compositions significantly changed. The relative abundance of some beneficial bacteria such as Lachnospiraceae, Ruminococcaceae, Ruminiclostridium, Eubacterium and Barnesiella significantly decreased and subsequently increase with age, which contributes to maintain the stability of intestinal environment and realize the diversity of intestinal functions. The relative abundance of Porphyromonas, Brevundimonas, Flavobacterium, Stenotrophomonas, Propionibacterium, Acinetobacter, Enterococcus and Clostridium belong to pathogenic bacteria in milk replacer-treated YBGs was significantly decreased. Additionally, some beneficial bacteria such as Ruminococcus, Ruminococcaceae, Christensenellaceae and Ruminiclostridium also display a trend of decreasing first followed by gradually increasing.

Conclusions

This study first revealed the gut bacterial community alterations in YBGs with the effect of age and milk replacer. This study also characterized the gut microbial distribution in YBGs with different ages and provided better insight into microbial population structure and diversity of YBGs. Moreover, milk replacer may serve as a good applicant for improving gut microbial development in early-weaned YBGs.

Milk Replacer Supplementation Ameliorates Growth Performance and Rumen Microbiota of Early-Weaning Yimeng Black Goats

Increasing evidence has indicated the ameliorative effect of milk replacer supplementation in ruminants for regulating their early growth and rumen development. However, it is still unclear whether milk replacer supplementation has a beneficial role in the growth performance and rumen microbiota of Yimeng black goats (YBGs). Therefore, this study was performed to investigate the effects of milk replacer on growth performance and rumen microbiota of YBGs. Our results revealed that milk replacer supplementation could significantly improve the growth performance of YBGs. Additionally, the results of alpha and beta diversities indicated that there was no significant difference in richness and diversity between the control and milk replacer-treated YBGs. At the phylum level, Bacteroidetes, Firmicutes, and Proteobacteria were the most dominant phyla in all the samples at different stages. Moreover, the YBGs treated with milk replacer possessed a higher abundance of Verrucomicrobia than that in the control YBGs, while the level of Actinobacteria was obviously decreased. It is noteworthy that the abundance of Proteobacteria in the control YBGs was higher than that in the YBGs supplemented with milk replacer throughout the experiment. At the level of genus, the differences in the richness between control and milk replacer supplement YBGs were gradually observed. Compared with the control YBGs, the proportion of Akkermansia, Veillonella, Anaerovibrio, Ruminococcaceae_NK4A214_group, Ruminococcus_1, and Ruminococcus_2 was increased in the YBGs treated with milk replacer, whereas Turicibacter was decreased. In conclusion, milk replacer supplementation may serve as a good applicant for ameliorating early YBGs development and rumen microbiota.

Stall feeding of sheep and goats: An alternative system to traditional grazing on community lands

Sheep and goats in the country are mostly raised on grazing resources. But these resources are gradually shrinking over the periods both in term of areas under them and also in yield and quality. On the contrary, populations of sheep and goat are increasing rapidly to meet the demand of meat. This is resulting in overstocking and overcrowding on available grazing lands and sharp deterioration of grazing resources. The intensive system (stall feeding) as an alternative to traditional grazing and semi-intensive system, may be useful to maintain pace with growing meat demand in the changing scenario of grazing resources in the country. Studies have shown that lambs and kids on stall feeding with adequate nutrition and management attain faster growth, attain slaughter weights at an early age and produce heavier carcass weights, more dressing yield and desirable lean, fat and bone contents. Although initially intensive system seems costly due to more feed cost and more capital investment, but this is justified by higher economic returns to farmers. Therefore, it can be concluded that intensive feeding system for sheep and goats is better than extensive system and at par or better than semi-intensive system for lamb and kid fattening purpose from 3–6 months of age. This review article also discusses the possibility of economic viability of sheep and goats rearing under stall feeding.

Effects of spirulina supplementation on lipid metabolism disorder, oxidative stress caused by high-energy dietary in Hu sheep

The aim of this study was to investigate the effect of spirulina supplementation in a high-energy (HE) diet on lipid metabolism, oxidative status and immunity in Hu lambs. The lambs were assigned to two groups receiving either a standard diet (ST) or a HE diet. Each group was divided into three subgroups: no spirulina supplementation (control), 1% spirulina supplementation, or 3% spirulina supplementation. The body fat, serum cholesterol, triacylglycerol and oxidative stress increased in lambs fed the HE diet. However, 3% spirulina supplementation in the HE diet reduced above parameters and enhanced antioxidant capacity, including increased SOD activity and T-AOC content in serum and Longissimus thoracis et lumborum (LTL). Additionally, lambs receiving 3% spirulina supplementation showed an improvement in immunity-related parameters, including increased IgG concentration in serum and red and white blood cell counts. In conclusion, 3% spirulina supplementation in HE diet ameliorated lipid metabolic disorder and oxidative stress caused by a HE diet.

Impact of early weaning on small intestine, metabolic, immune and endocrine system development, growth and body composition in artificially reared lambs

AbstractThis study evaluated the effect of early weaning (EW) of artificially reared lambs using a restricted milk replacer (MR) feeding and step-down weaning system on the short- and long-term effects on growth, feed intake, selected blood metabolites and hormones, body composition, and small intestine development. Mixed-sex twin-born 2 to 5 d old lambs were randomly allocated to individual pens and fed MR at 20% of initial individual BW in week 1 and 15% in week 2 followed by weaning off MR by the end of week 4 (EW; n = 16) or week 6 (Control; Ctrl, n = 16) using a step-down procedure. Concentrate starter and fiber diets were offered ad libitum to week 9, then gradually removed over a 10-d period. All lambs were managed as a single group on pasture from weeks 6 to 16 of the trial. Feed intake was recorded daily in the first 6 wk, and BWs recorded weekly. At weeks 2, 4, 6, and 8, and pre- and postclostridial vaccination at week 8, blood samples were collected for analysis of selected blood metabolites, IGF-1, and immune function. Body composition was evaluated in eight animals per group at weeks 4 and 16 after euthanasia, and duodenal samples collected for histomorphometric evaluation. Early weaned lambs had lower DM, ME, CP, and NDF intake than Ctrl lambs at 21, 15, 21, and 36 d of rearing, respectively (P < 0.001), driven by lower intakes of MR from day 15 (P < 0.001) as per the experimental design, and lower total DMI of fiber (P = 0.001) from 21 to 42 d of rearing. Lamb BW tended (P = 0.097) to be lower in EW than Ctrl lambs from 5 to 10 wk of rearing, with lower ADG in EW lambs from weeks 3 to 6 (P = 0.041). Early weaning had negligible effects on duodenal morphology, organ, and carcass weights at weeks 4 and 16. Plasma metabolites (urea nitrogen, triglycerides, NEFA, glucose, and total protein) were similar between groups, while β-hydroxybutyrate was greater in EW than Ctrl lambs at weeks 4 and 6 (P = 0.018) but not week 8 indicative of early rumen development. Serum IGF-1 tended to be lower in EW than Ctrl lambs from weeks 2 to 6 only (P = 0.065). All lambs developed antibody responses postvaccination and there was no effect of treatment (P = 0.528). The results of this study illustrate that artificially reared lambs can be weaned off MR by 4 or 6 wk of rearing without compromising growth, small intestine morphology, major organ development, and body composition, nor immune function at either 4 (preweaning) or 16 (postweaning) wk of age.

Weaning Ages Do Not Affect the Overall Growth or Carcass Traits of Hu Sheep

This study aimed to determine effects of weaning ages on growth, rumen development, and carcass characteristics and meat quality of Hu lambs. Thirty male Hu lambs were randomly divided into two weaning age groups: Weaned at 30 (W30) or 45 (W45) d of age. Blood samples were collected on the day of weaning before lambs (n = 5) were slaughtered, and then rumen sample was collected immediately after they were slaughtered. The intake of all feeds increased with age (p < 0.05), but were not affected by weaning age (p > 0.05). Oxidative stress indicators and immune variables, the plasma biochemical parameters did not differ between the two different weaning ages (p > 0.05). The two weaning age groups also had similar (p > 0.05) concentration of ruminal total volatile fatty acid. The two weaning age groups did not differ in body weight, carcass characteristics, or meat quality (p > 0.05) at d 120. These results indicate that weaning half a month earlier than the typical weaning age does not significantly affect the growth, ruminal development, or carcass characteristics of Hu lambs, and they can be weaned at 30 d of age to improve production efficiency.

Growth performance and economics of pre-weaner lambs fed gelatinized and non-gelatinized milk replacer

Influence of milk replacer feeding to lambs was assessed on pre-weaning growth and nutrient utilization. Seven day old Malpura lambs (45) were divided into three groups of fifteen lambs in each group and were fed ad lib. creep mixture and roughage (C-0; Control) along with free suckling of dam. Unlike control (C-0), the lambs in two treatment groups were additionally fed with gelatinized (MR-G) and non-gelatinized (MR-Ng) milk replacer with limited suckling from their dam, which were manually milked once in the afternoon (4.00 PM). The MR was fed at 100 ml/lamb/day for first fifteen days and thereafter at 250 ml/lamb/day. The experimental feeding including a digestibility trial was continued until weaning at 3 months of age. Weaning weight, total gain and ADG was higher in MR-G compared to MR-Ng and control and there was 15.25% improvement in MR-G than the control. A lower value of FCR indicated 10.5% improvement in MR-G than the control. The plane of nutrition and digestibility of DM, OM, CP, NDF, hemicellulose was similar in all the three groups. The total milk collected/ewe in MR-G and MR-Ng group was 9.0 kg each that fetched rs. 360 and it reduced the production cost to rs. 51.0 in MR-G, 53.1 in MRNg compared to rs. 68.1 in C-0. One time milking of ewes and replenishment with additional milk replacer to lambs promises higher gain and introduction of the gelatinization procedure ensures further improvement in FCR and ease in delivery to lambs.

Effect of different feeding regimens on energy and protein utilization and partitioning for maintenance and growth in pre-weaned lambs reared artificially

Estimation of metabolizable energy (ME) requirement for maintenance (ME) and growth (ME) in pre-weaned lambs have been limited to milk-only fed lambs. This study aimed to determine energy and nitrogen metabolisability of milk and pellets when fed together, compare the growth and chemical body composition of lambs fed varying levels of pellets in addition to milk, and to estimate ME, ME, and the CP:ME ratio requirements for growth. The study included 32 twin-born Romney-cross ram lambs. Four lambs were slaughtered at 24 h post-partum to estimate initial body composition and the remaining 28 were assigned to 1 of 4 treatment groups of 7. Group 1 was fed milk replacer (MR) only; group 2 was fed MR and allowed ad libitum access to pellets; groups 3 and 4 were offered 30% and 60%, respectively of the average pellet intake of the ad libitum group the previous day while being fed MR. Milk replacer was fed as a proportion of the lamb's live weight (LW). Lambs from each treatment were placed in metabolic cages at 17 kg LW for 4 d to allow for total fecal and urine collection. All lambs were slaughtered at 18 kg LW. The ADG, ADG:ME ratio, stomach and liver weight, and rumen papillae lengths increased ( < 0.05) with increasing pellet intake. Increasing daily ME intake increased ( < 0.05) both daily energy and protein deposition but had no effect ( > 0.05) on fat deposition. However, the total chemical body composition was unaffected ( > 0.05) by dietary treatment. Digestibility of energy and N decreased ( < 0.05) with increasing ME intake. Percent energy and N retained for growth were 96% vs. 71% and 72% vs. 30% for milk and pellets, respectively. The ME and ME values obtained were 0.40 MJ ME/kg LW·d and 13.8 MJ ME/kg ADG, respectively. The CP:ME ratio of MR and pellet was 11.1 and 15.7, respectively. However, a simulation model suggested that lambs require a CP:ME ratio of 13.1 at 5 kg and 10.9 at 18 kg LW, indicating that protein intake may be limiting to lamb growth in early life and in excess by 18 kg LW. In conclusion, increasing pellet intake was associated with decreased N retention. The inclusion of pellets, however, improved the efficiency of ME utilization for growth in pre-weaned lambs and was beneficial for rumen development. The ME was higher than previously recommended values and the CP:ME intake of lambs does not match their requirements which may warrant further studies.

Enhancement of growth performance in pre-weaning suckling Boer kids supplemented with creep feed containing alfalfa

Aim:

This study examined the effects of creep feed (CF) supplementation (with or without Alfalfa) on the pre-weaning growth performance of nursing goat kids.

Materials and Methods:

A total of forty eight (48), 7 days old, single born kids (live weight 4.4±0.09 kg) were divided into three treatment groups, each containing eight males and eight females. All three groups had access to their dams’ milk (DM). The kids from the first treatment group had free access to CF containing alfalfa (CFA) while those from the second group had free access to CF without alfalfa. The third treatment group (control) had access to their DM only. All three groups were kept isolated from the dams from 800 to 1200 h and from 1400 to 1800 h while having access to CF.

Results:

Total weight gain and average daily gain of kids from CFA group (11.2±0.36 kg, 145.2±4.64 g) was significantly higher (p<0.05) than kids from CF (7.9±0.49 kg, 102.9±6.43 g) and DM (5.5±0.43 kg, 71.1±5.56 g) groups. The weaning weight of kids from CFA group (15.6±0.39 kg) was significantly higher (p<0.05) than those from CF (12.1±0.56 kg) and DM (9.9±0.59 kg) groups.

Conclusion:

This result shows that supplementation of CF combined with alfalfa from birth to weaning enhances growth performance of cross-bred Boer goat kids.

Effects of weaning age on growth, nutrient digestibility and metabolism, and serum parameters in Hu lambs

This study was conducted to investigate the effect of weaning age on growth performance, nutrient digestion and metabolism, and serological indicators, and to obtain an optimal weaning age in Hu lambs. Forty-eight newborn Hu lambs (birth weight, 2.53 ± 0.14 kg) were randomly divided into 4 groups. The lambs in control group (ER) suckled their dams. The lambs in other three experimental groups were weaned on milk replacer at 10, 20, and 30 days of age (EW10, EW20, and EW30 groups), respectively. The results were as follows: 1) lambs in EW10 and EW30 groups had a lower (P < 0.05) ADG than those in ER group within 10 days post-weaning; the weaned lambs began to show a higher (P < 0.05) ADG than those in ER group after 20 days post-weaning. 2) EW10 and EW20 groups had a higher (P < 0.05) creep feed intake than EW30 and ER groups from 15 to 60 days of age. 3) The apparent digestibility of dry matter, organic matter, gross energy, nitrogen, ether extract and phosphorus, and the deposition of nitrogen and phosphorus did not differ (P > 0.05) among groups; however, the apparent digestibility and deposition of calcium in early weaned lambs were lower (P < 0.05) than those in ewe-reared lambs. 4) The albumin content in EW30 group was lower (P < 0.05) than that in ER group; the globulin content in EW30 group was higher (P < 0.05) than that in other groups; the content of serum insulin-like growth factor-Ⅰ in weaned lambs tended to increase compared with lambs in ER group. Finally, the growth rate of lambs decreased within 10 days post-weaning, but early weaning boosted creep feed intake, leading to better growth and health later in life. The Hu lambs can be weaned on milk replacer and creep feed at 10 days of age.

Growth performance of lambs fed diet supplemented with rice bran oil as such or as calcium soap

Forty two Malpura lambs (21 d old) were divided into three groups of 14 each consisting of 8 females and 6 males. Lambs were allowed to suckle their respective dams twice daily up to weaning (13 wks) and offered free choice concentrate and roughage in a cafeteria system. The lambs in control group were fed conventional concentrate mixture, in RBO group concentrate mixture fortified with 4% industrial grade rice bran oil and in Ca-soap rice bran oil (as in RBO group) was supplemented in the form of calcium soap. The concentrate intake decreased(p≤0.05) in RBO group as a result total dry matter, crude protein and metabolizable energy intake decreased compared to control whereas Ca-soap prepared from the same rice bran oil stimulated the concentrate intake leading to higher total dry matter, crude protein and energy intakes. The digestibility of dry matter (p≤0.05), organic matter (p≤0.05) and crude protein (p≤0.05) was higher in RBO group followed by Ca-soap and control whereas no effect was observed for ether extract digestibility. Higher cholesterol (p≤0.05) content was recorded in serum of oil supplemented groups (RBO and Ca-soap) while no effect was recorded for other blood parameters. Rice bran oil as such adversely affected and reduced the body weight gain (p≤0.001) of lambs in comparison to control whereas the Ca-soap of rice bran oil improved body weight gain and feed conversion efficiency in lambs. Fat supplementation decreased total volatile fatty acids (p≤0.05) and individual volatile fatty acid concentration which increased at 4 h post feeding. Fat supplementation also reduced (p≤0.05) total protozoa count. Ca-soap of rice bran oil improved pre slaughter weight (p≤0.05) and hot carcass weight (p≤0.05). It is concluded from the study that rice bran oil in the form of calcium soap at 40 g/kg of concentrate improved growth, feed conversion efficiency and carcass quality as compared to rice bran oil as such and control groups.

Some gastrointestinal tract characteristics of Karayaka ram lambs slaughtered at different weights

Thirty-one Karayaka ram lambs were slaughtered at different body weights (30 (n =  7), 35 (n =  6), 40 (n =  7), 45 (n =  6), and 50 (n =  5) kg of body weight at fast) to evaluate the growth of their gastrointestinal tract (GIT) characteristics, to determine the relationship among slaughter body weight (SBW) and empty body weight (EBW), whole GIT and segments, and the influence of slaughter weight on the pH of rumen, jejunum, and cecal contents. The effects of the SBW on GIT weight (P <  0.05), stomach (P <  0.001), and intestine (P <  0.05), the body length (P <  0.001) and caecum (P <  0.05), and the relative weights of GIT (P <  0.05), stomach (P <  0.001), and intestine (P <  0.001) were linear whereas that for the length of intestine were quadratic. The effect of SBW were quadratic (P <  0.05) on ratios of stomach to GIT weight and intestine length to intestine weight and rumen pH while, for the intestine to GIT weight ratio (P <  0.001) and caecum pH (P <  0.05), this effect was linear. The results indicated that for all parameters studied, with the exception of intestinal length and cecal pH, linear relationships were observed with SBW indicating steady growth rates for these tissues.

Effect of milk replacer and rumen inert fat on growth and reproduction of Malpura ram lambs

The objective of this study was to assess the effects of milk replacer and rumen inert fat on growth, testicular development, puberty, semen production and sperm motion characteristics of ram lambs reared under intensive management in semi-arid climatic conditions. Seven-day-old male lambs of Malpura breed (n=20) were divided equally into two groups. Up to weaning, the lambs in G1 group (control) were fed concentrate, green khejri (Prosopis cineraria) leaves and cowpea (Vigna unguiculata) hay along with suckling of dams, whereas lambs in G2 group were fed reconstituted milk at 17 g/lamb per day for the 1st week and at 34 g/lamb per day from 2nd week in addition to the feed inputs given in G1. During post weaning, lambs in the G1 group were given control concentrate, whereas in G2 the control concentrate supplemented with 40 g rumen inert fat per kg of feed was offered along with dry pala (Zizyphus nummularia) and ardu (Ailanthus excelsa) leaves. BWs of lambs were recorded weekly up to 6 months of age. Ram lambs of both the groups were trained for semen collection at a weekly interval from the age of 5 months and simultaneously testicular measurements were recorded fortnightly. The feeding of milk replacer and rumen inert fat had positive (P<0.05) effects on BW, testicular length, testicular volume, semen volume, sperm concentration, mass motility, % motility, % rapid, medium or slow motile spermatozoa. However, no significant effect was observed on testicular breadth, scrotal circumference, age of puberty, sperm velocities and other CASA-derived parameters. The results of this study indicate that higher plane of nutrition in the form of milk-replacer feeding during preweaning and rumen inert fat-supplemented feed during the postweaning period to growing ram lambs enhances their growth, testicular development and semen quality.