Growth Performance Of Lambs Research Articles

Effect of grape pomace supplement on growth performance, gastrointestinal microbiota, and methane production in Tan lambs.

Grape pomace (GP), a by-product in wine production, is nutritious and can be used as a feed ingredient for ruminants; however, its role in shaping sheep gastrointestinal tract (GIT) microbiota is unclear. We conducted a controlled trial using a randomized block design with 10 Tan lambs fed a control diet (CD) and 10 Tan lambs fed a pelleted diet containing 8% GP (dry matter basis) for 46 days. Rumen, jejunum, cecum, and colon bacterial and archaeal composition were identified by 16S rRNA gene sequencing. Dry matter intake (DMI) was greater (p < 0.05) in the GP than CD group; however, there was no difference in average daily gain (ADG, p < 0.05) and feed conversion ratio (FCR, p < 0.05) between the two groups. The GP group had a greater abundance of Prevotella 1 and Prevotella 7 in the rumen; of Sharpe, Ruminococcaceae 2, and [Ruminococcus] gauvreauii group in the jejunum; of Ruminococcaceae UCG-014 and Romboutsia in the cecum, and Prevotella UCG-001 in the colon; but lesser Rikenellaceae RC9 gut group in the rumen and cecum, and Ruminococcaceae UCG-005 and Ruminococcaceae UCG-010 in the colon than the CD group. The pathways of carbohydrate metabolism, such as L-rhamnose degradation in the rumen, starch and glycogen degradation in the jejunum, galactose degradation in the cecum, and mixed acid fermentation and mannan degradation in the colon were up-graded; whereas, the pathways of tricarboxylic acid (TCA) cycle VIII, and pyruvate fermentation to acetone in the rumen and colon were down-graded with GP. The archaeal incomplete reductive TCA cycle was enriched in the rumen, jejunum, and colon; whereas, the methanogenesis from H2 and CO2, the cofactors of methanogenesis, including coenzyme M, coenzyme B, and factor 420 biosynthesis were decreased in the colon. The study concluded that a diet including GP at 8% DM did not affect ADG or FCR in Tan lambs. However, there were some potential benefits, such as enhancing propionate production by microbiota and pathways in the GIT, promoting B-vitamin production in the rumen, facilitating starch degradation and amino acid biosynthesis in the jejunum, and reducing methanogenesis in the colon.

Effects of sea-buckthorn flavonoids on growth performance, nutrient digestibility, microbial protein synthesis, and plasma antioxidant capacity of finishing lambs

Sea-buckthorn flavonoids (SFs) are a type of natural antioxidants that have attracted considerable attention because of their extensive biological functions and regulatory effects on animal physiology. This study evaluated the effects of dietary SFs supplementation on growth performance traits, apparent nutrient digestibility, rumen fermentation, microbial protein synthesis, and antioxidant capacity of finishing lambs. In total, forty-eight 1/2 Dorper (♂) × 1/2 Small thin-tailed (♀) crossed male lambs (body weight = 22.5 ± 1.33 kg, mean ± SD) were randomly allocated to one of the four treatment groups (n = 12 lambs/group): basal diet supplemented with 0 (CON), 1.0 (LSFs), 3.0 (MSFs), and 5.0 (HSFs) g SFs/kg diet (dry matter basis). After 60 days of feeding experiment, six lambs were randomly selected from each group for 10 days of digestion and metabolism experiment. The results showed that lambs in the MSFs group had significantly higher ADG than those in CON group (P < 0.05), and both LSFs and MSFs group had higher DMI than the other groups (P < 0.05). The digestibility of DM in MSFs group was significantly higher than that in CON group (P < 0.05), and the digestibility of OM and NDF was also higher than that in CON and HSFs group (P < 0.05). The urinary nitrogen excretion of lambs in MSFs and HSFs groups was lower than that in CON and LSFs groups, therefore, the dietary nitrogen retention was significantly increased (P < 0.05). Rumen fermentation results showed that acetate and total volatile fatty acids (VFA) concentrations in MSFs and HSFs groups were higher than those in other groups (P < 0.05), and the microbial proteins (MCP) yield in MSFs group was also significantly increased compare with the CON group. In addition, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in plasma of lambs in MSFs and HSFs groups were significantly increased, while the content of malondialdehyde (MDA) was significantly decreased (P < 0.05). Therefore, SFs are beneficial for growth performance, rumen fermentation, and serum antioxidant capacity in lambs and could be used as a natural feed additive in lamb production.

Wheat silage partially replacing oaten hay exhibited greater feed efficiency and fibre digestion despite low feed intake by feedlot lambs

This study aimed to investigate the feeding effect of wheat silage on growth performance, nutrient digestibility, rumen fermentation, and microbiota composition in feedlot lambs. Sixty-four male crossbred Chinese Han lambs (BW = 27.8 ± 0.67 kg, 3 months of age) were randomly assigned to four ration groups with wheat silage replacing 0% (WS0), 36% (WS36), 64% (WS64), and 100% (WS100) of oaten hay on forage dry matter basis. The concentrate-to-forage ratio was 80:20 and the feeding trial lasted 52 d. Increasing wheat silage inclusion linearly decreased dry matter intake by 4% to 27% (P < 0.01). However, increasing the wheat silage replacement of oaten hay by no more than 64% improved the feed efficiency by 14% as noted by the feed-to-gain ratio (P = 0.04). Apparent digestibility of organic matter (P < 0.01), neutral detergent fibre (P = 0.04) and acid detergent fibre (P < 0.01) quadratically increased. Ammonia nitrogen (P = 0.01) decreased while microbial protein production (P < 0.01) increased with the increase of wheat silage inclusion. Total volatile fatty acids concentration increased quadratically with the increase of wheat silage inclusion (P < 0.01), and the highest occurred in WS64. The molar proportion of acetate (P < 0.01) and acetate-to-propionate ratio (P = 0.04) decreased while butyrate (P < 0.01) and isovalerate (P = 0.04) increased. Increasing wheat silage inclusion increased the Firmicutes-to-Bacteroidota ratio by 226% to 357%, resulting in Firmicutes instead of Bacteroidota being the most abundant phylum. The relative abundance of cellulolytic Ruminococcus numerically increased but that of amylolytic Prevotella (P < 0.01) decreased as increasing wheat silage inclusion. Taken together, increasing wheat silage replacement of oaten hay by no more than 64% exhibited greater feed efficiency and fibre digestion despite low feed intake by feedlot lambs due to the change of Firmicutes-to-Bacteroidota ratio in the rumen.

Growth Performance and Ruminal Fermentation in Lambs with Endoparasites and In Vitro Effect of Medicinal Plants

We investigated growth performance and ruminal fermentation associated with gastrointestinal nematode (GIN) Haemonchus contortus in lambs and in vitro ruminal fermentation of mallow, chamomile, fumitory, wormwood (Herbmix), and chicory using inoculum from GIN-infected lambs. Twelve lambs were equally divided into two groups: uninfected animals (CON) and animals infected (INF) with approximately 5000 third-stage larvae derived from the MHCo1 strain of GIN H. contortus. Two lambs per group were killed on days 48, 49, and 50 after infection and ruminal content was collected separately from each lamb. Batch cultures of ruminal fluid from CON and INF were incubated for 24 h in vitro with 0.25 g meadow hay, Herbmix, and chicory using an in vitro gas production technique. Daily weight gain was relatively lower in the INF than the CON group, but not significantly (72.6 vs. 130.1 g/day). The ruminal populations of protozoa, bacteria, total Archaea, Methanobacteriales, and Methanomicrobiales were significantly higher in the INF than in the CON group. The substrates affected the concentrations of n-butyrate, iso-butyrate, n-valerate, iso-valerate, ammonia-N, total gas, and methane (p &lt; 0.001) in vitro. GIN infection affected fermentation and microbial population in the rumens of the lambs, and chicory was a promising substrate to modulate ruminal fermentation in vitro.

Evaluation of Growth Performance, Efficiency of Dietary Net Energy Utilization, and Carcass Trait Responses of Heavy Finishing Lambs Administered 12 mg of Zeranol Subcutaneously in the Ear 59 d before Harvest

The objective of this research was to determine the influence of implanting heavy wether lambs with 12 mg of zeranol (1 pellet Ralgro, Merck Animal Health. Madison, NJ, USA) 59 d before harvest. Average daily gain (ADG), feed efficiency, and carcass merit were evaluated. Polypay and crossbred wethers (n = 32) were equally divided into two treatment groups: non-implanted; (CON) or implanted with 12 mg of zeranol (IMP) in a randomized complete block design. Sixteen pens were used, resulting in eight replicate pens per treatment. Wethers were fed a finishing diet consisting of cracked corn, soybean meal, and soybean hulls ad libitum for 59 d. Lambs had access to clean water at all times from water fountains. Lambs were weighed on d -1, 1, 14, and 59. On d 59, 16 lambs (8 lambs/treatment) were harvested in the South Dakota State University Meat Lab. Hot carcass weight (HCW), dressing percent (DP), rib fat, body wall thickness, loin eye area, boneless closely trimmed retail cut percentages, and yield grades were recorded. Final body weight (BW), cumulative ADG, and gain efficiency were greater (p ≤ 0.01) for implanted lambs by 2.9%, 25.0%, and 35.2%, respectively, while dry matter intake (DMI) was unaffected by implant treatment (p = 0.18); thus, the efficiency of dietary net energy utilization was increased for IMP (p ≤ 0.01). No appreciable differences were noted (p ≥ 0.17) between treatments for any carcass traits measured. These results indicate that zeranol improves growth performance in heavy finishing lambs without detriment to carcass quality, which implies that producers can improve profitability due to increased gains and efficiency.

Effects of melatonin implants on locomotor activity, body temperature, and growth of lambs fed a concentrate-based diet

Melatonin is involved in the regulation of circadian rhythms and is implicated in seasonal reproduction in sheep. In several physiological mechanisms, it acts as an antioxidant and an anti-inflammatory molecule, regulating energy metabolism. This work investigated the effects of melatonin implants at 30 days of age on locomotor activity (LA), body temperature, and growth of fattening female and male lambs. Sixty lambs were divided into two groups: one of which received melatonin (MEL, 15 males, 16 females) and a control group (CTR, 16 males, 14 females). In the melatonin group, two 18 mg melatonin implants were placed at 30 days of age. Lambs were fattened for 6 weeks from weaning (45 days of age) to slaughter (85 days). The feed conversion rate (FCR) was calculated based on live weight and the amount of concentrate consumed. LA was measured weekly by actigraphy, and circadian rhythmicity was calculated. Rectal (Trec) and surface temperatures (Tsur) were recorded in the last week of fattening, and subcutaneous fat thickness (FT) over the longissimus dorsi muscle was measured by ultrasound scanning. Treatment did not affect FCR, although MEL female lambs consumed significantly (P < 0.001) less concentrate than CTR lambs. Treatment and sex had a significant (P < 0.05) interaction effect on FT; specifically, FT was significantly (P < 0.05) higher in female MEL lambs (3.22 ± 0.21 mm) than in female CTR lambs (2.57 ± 0.24 mm), but FT in males did not differ between MEL (2.77 ± 0.21) and CTR (2.94 ± 0.24 mm) lambs. Overall activity was significantly (P < 0.001) lower in the MEL lambs (72.22 ± 0.10 counts/min) than in the CTR lambs (78.89 ± 0.12 counts/min). MEL lambs had a significantly (P < 0.01) lower Trec (CTR: 39.00 ± 0.07; MEL: 38.68 ± 0.10) and Tsur for all body regions evaluated than the CTR lambs. In conclusion, treatment with exogenous melatonin at 30 days of age increased food efficiency in fattening female lambs, probably, because of the lower metabolism in treated lambs, which was reflected by the lower body temperature and LA exhibited by these animals. In addition, the study has demonstrated the effect of exogenous melatonin in the growth performances of post-weaning lambs, and that its effects depend on animal sex, which suggests that treatments that target females might be most appropriate in the fattening period.

Características reproductivas y productivas en ovejas Bafra (Chios × Karayaka), crecimiento, rendimiento de la canal y supervivencia de los corderos

This study was carried out on Bafra (Chios × Karayaka) breed to determine the fertility characteristics of sheep, growth performance, survivability and carcass weights of lambs. For this purpose, the reproductive characteristics of 600 sheep aged 2–5 years and the survivability of 1,150 lambs born from these sheep were determined. In addition, the growth performance characteristics, slaughter, and carcass weights of 65 lambs born from 38 randomly selected ewes 3–4 years old were determined. In the study, the pregnancy rate was 90.00%, the birth rate was 87.16%, singleness 15.00%, twins 80.00%, and triplet 5.00%, lamb yield per ewe 1.90, number of lambs per birth 2.20 was calculated. Birth and weaning (90th d) weights as well as 61–90th d of live weight gains of male and female lambs were found as 4.26 and 3.57 kg, 24.15 and 21.32 kg, 265.75 and 231.72 g, respectively. The 120th d survivability, slaughter and carcass weights and carcass yields of lambs were determined as 97.74%, 47.10 kg, 21.61 kg and 45.92%, respectively. As a result, although the Bafra sheep is a breed that can be recommended to be raised in terms of the characteristics discussed, more scientific research is needed on it.

Stall-Feeding of Sheep on Restricted Grazing: Effects on Performance and Serum Metabolites, Ruminal Fermentation, and Fecal Microbiota.

This study investigated the effects of three feeding systems, indoor feeding (CONT), indoor feeding with time-restricted grazing artificial pasture (4 h/day, G4H), and indoor feeding with an eight-hour daily grazing artificial pasture (G8H), on the growth performance, serum metabolites, ruminal fermentation, and fecal microbiota composition of lambs. Average daily gain showed a tendency (p = 0.081) to be higher for the G4H group compared with the CONT group. Moreover, feeding systems did not have a significant effect on most of the serum biochemical indicators in lambs. Concentrations of serum glutathione peroxidase and immunoglobulins (IgA, gG, and IgM) were significantly lower (p < 0.01) in the CONT group. Additionally, a tendency towards higher levels of volatile fatty acids, acetate, and butyrate was found in animals of the G4H group compared to the CONT group. Furthermore, fecal microbiota composition was altered in G4H and G8H groups, resulting in the increased relative abundance of Firmicutes and Ruminococcaceae UCG-005, as well as the decreased relative abundance of Ruminobacter compared with the CONT group. Overall, these results suggest that indoor feeding with restricted grazing time does not significantly affect fattening performance or rumen fermentation but enhances antioxidation and immune function activity and also alters fecal microbiota composition.

Feed intake, digestibility, ruminal fermentation, growth performance, and carcass traits of lambs fed corn silage treated with Lentilactobacillus buchneri and stored for different times

Our objective was to investigate the impact of inoculation and storage length of flint corn silage on the metabolic and production responses of lambs. A flint corn hybrid was harvested with 315 g dry matter (DM)/kg and ensiled in concrete pipe silos without (control) or with Lentilactobacillus buchneri CNCM I-4323 at 1 × 105 cfu/g of fresh forage for 120, 240 and 360 d (n = 2 for each treatment). Such silages were used to formulate six different diets. Sixty non-castrated male Dorper × Santa Inês lambs were used in the feeding program (n = 10). Additionally, eight ruminally cannulated Dorper × Santa Inês crossbred lambs were used to measure the ruminal fermentation (n = 4). Extending the storage of corn silage from 120 to 360 d increased the contents of soluble protein (P = 0.030; 415–490 g/kg CP) and ammonia-N (P = 0.047; 82.5–114 g/kg total N). Compared to the control, inoculation resulted in higher (P < 0.05) concentration of lactic (+19.9 %) and acetic acid (+38.6 %), and lower butyric acid (–25.3 %), ammonia-N (–23.5 %), and DM loss (–36.2 %). The aerobic stability of corn silage was also improved by inoculation (P = 0.002; +160 h compared to the control). An interaction between storage length and inoculation was reported for feed intake, and lambs had increased DMI (P < 0.001) by feeding the inoculated silage stored for 120 d. Overall, the total-tract starch digestibility increased (P = 0.041) with longer storage (120 d = 94.4 %; 240 d = 95.7 %; 360 d = 96.5 %). However, the total VFA was unchanged (P > 0.05) while the ruminal molar proportion of propionate decreased from 22.8 to 20.7 mM/100 mM in lambs fed corn silage stored for 120 and 360 d (P = 0.004). Lengthening silage storage from 120 to 240 and 360 d tended (P = 0.06) to increase the ADG of lambs by 4.6 % and 10.2 %, respectively (120 d = 0.216 kg/d; 240 d = 0.226 kg/d; 360 d = 0.238 kg/d). Moreover, the feed efficiency was substantially improved (P = 0.008) by 5 % and 14 % when the silages were stored for 240 and 360 d compared to 120 d. In opposite, inoculation had no effect (P > 0.05) on ADG and feed efficiency of lambs. Final hot carcass weight (data ranged from 16.8 to 17.2 kg) and 12th rib longissimus muscle area (data ranged from 13.8 to 14.7 cm2) were not affected by treatments (P > 0.05). Overall, only few parameters of carcass and meat traits of lambs were altered by storage length and inoculation, but it were of minor biological importance. In conclusion, the productivity responses of lambs were enhanced by increasing the storage length of flint corn silage, but inoculation with L. buchneri did not contribute to improve animal performance.

Effect of Dietary Calcium Propionate Inclusion Period on the Growth Performance, Carcass Characteristics, and Meat Quality of Feedlot Ram Lambs

The objective was to determine the effect of calcium propionate (CaPr) inclusion in the diet, at different periods on the growth performance, carcass characteristics, and meat quality of finishing lambs. Thirty-six Dorper × Katahdin crossbred male lambs (39.1 ± 0.44 kg BW) were housed in individual pens during a 42 d feeding period and assigned to four treatments (n = 9) consisting of CaPr administered at a dose of 10 g/lamb/d for 0 (control), 14, 28, or 42 d before slaughter. Final BW (FBW), average daily gain (ADG), dry matter intake (DMI), and ADG:DMI ratio increased quadratically (p &lt; 0.05) by CaPr supplementation, being optimal at an estimated inclusion period of 25 d for FBW and ADG, 15 d for DMI, and 28 d for ADG:DMI ratio. Hot carcass weight (HCW), cold carcass weight (CCW), and dressing were quadratically improved (p &lt; 0.05) at an estimated inclusion period of 24 d for HCW and CCW, and 20 d for dressing. The increased inclusion period (42 d) augmented fat thickness (linear effect, p &lt; 0.05). At 28 d of CaPr supplementation, maximal response (quadratic effect, p &lt; 0.05) was estimated in the empty body weight at 28 d, forequarter at 26 d, and neck at 24 d, but a longer inclusion period (42 d) increases the weight of leg and rack and reduced the proportion of loin as a percentage of CCW (linear effect, p &lt; 0.05). In conclusion, dietary CaPr can be included for a period of 24 to 28 d to improve growth performance and carcass weight, without affecting organ mass or meat quality.

Influence of probiotic supplementation on the growth performance, plasma variables, and ruminal bacterial community of growth-retarded lamb.

Growth-retarded lambs would reduce the economic incomes of sheep farming. Nutritional interventions are supposed to promote gastrointestinal health and the compensatory growth of growth-retarded lambs. This study evaluated the effects of probiotic supplementation on the growth performance, plasma characteristics and ruminal bacterial community of growth-retarded lambs. Twenty-four 50-days old male Hu lambs, including 8 healthy lambs (13.2 ± 1.17 kg) and 16 growth-retarded lambs (9.46 ± 0.81 kg), were used in this study. The 8 healthy lambs were fed the basal diet and considered the positive control (GN), and the other 16 growth-retarded lambs were randomly assigned into 2 groups (basal diet without probiotic [negative control, GR] and basal diet supplementation with 1 g/kg concentrate feed probiotic [GRP]), with each group having 4 replicate pens. The feeding trial lasted for 60 days with 7 days for adaptation. The results showed that dietary supplementation with probiotic increased (p < 0.05) the average daily gain and dry matter intake of growth-retarded lambs. For growth-retarded lambs, supplementation with probiotic increased (p < 0.05) the activities of superoxide dismutase and glutathione peroxidase, as well as the concentrations of growth hormone and immunoglobulin G. Furthermore, the highest (p < 0.05) concentrations of interleukin-6, interferon-gamma and tumor necrosis factor alpha were observed in the GR group. The concentrations of total volatile fatty acids and acetate in growth-retarded lambs were increased by probiotic supplementation (p < 0.05). The relative abundances of Ruminococcus, Succiniclasticum and Acidaminococcus were lower (p < 0.05) in growth-retarded lambs. However, probiotic supplementation increased (p < 0.05) the relative abundances of these three genera. These results indicate that dietary supplementation with probiotic are promising strategies for improving the growth performance of growth-retarded lambs by enhancing immunity and altering the ruminal microbiota.

Effect of maternal experience and body condition on patterns of ewe-lamb bonding behaviors and pre-weaning growth performance of lambs

Many factors, involving parity and body condition can have a profound effect on physiological and sensory determinants of maternal behavior and, consequently, the establishment of the ewe-lamb bond. Thus, exploring the factors and their interactions that influence maternal behavior is critical to improve the overall lamb survival and welfare. The aim of this study was to determine the effects of parity and body condition score (BCS) on early ewe–lamb bonding behaviors and pre-weaning growth performance in lambs. The study was carried out with 12 first-parity (primiparous; PP), 12 second-parity (biparous: BP), and 14 third or more parity (multiparous: MP) Norduz ewes and 38 singleton lambs. In the study, ewe–lamb bonding behaviors were analyzed based on parity (PP, BP, and MP) and body condition score groups (BCS ≤ 3 and BCS > 3). Behaviors of ewes and lambs from each group were monitored for a period of 3 hours after parturition, and the ewe–lamb separation test was performed within the first 24 hours after parturition. Maternal behaviors such as latency to grooming, the number of low and high pitch bleats, and preventing sucking and neonatal behaviors such as latency to successful suck, the number of bleats and the total sucking duration were determined. The live weights of the lambs were recorded every 2 weeks until the 90th day. Ewes were grazed entirely on pasture without extra feed supplementation during the pasture season. Ewes were fed with alfalfa hay and gradually supplemented with barley and concentrate throughout the winter. While the grooming duration was not affected by parity, BCS > 3 ewes had longer grooming duration than BCS ≤ 3 ewes (P < 0.05). More prevention of sucking, butting, and low and high pitch bleating were counted for PP ewes than BP and MP ewes (P < 0.05). Parallel to these results, PP lambs had the longest latency to successful suck (P = 0.046) and the highest number of sucking attempts (P = 0.033). The mean sucking duration of MP lambs was significantly longer than PP lambs (P < 0.038). Birth weight of PP lambs was lower than MP lambs, but neither parity nor BCS had a significant effect on growth performance of lambs. In conclusion, the findings of the study showed that lack of maternal experience caused a negative effect on co-operation with lamb sucking attempts, but did not significantly affect growth performance. It can be suggested that BCS had little effect on maternal behavior and growth performance of lambs for ewes with a body condition score of 2.85-3.33 during the mating period.

Effects of rearing mode on gastro-intestinal microbiota and development, immunocompetence, sanitary status and growth performance of lambs from birth to two months of age

BackgroundArtificial rearing system, commonly used in prolific sheep breeds, is associated to increased mortality and morbidity rates before weaning, which might be linked to perturbations in digestive tract maturation, including microbiota colonization. This study evaluated the effect of rearing mode (mothered or artificially reared) on the establishment of the rumen and intestinal microbiome of lambs from birth to weaning. We also measured immunological and zootechnical parameters to assess lambs’ growth and health. GIT anatomy as well as rumen and intestinal epithelium gene expression were also analysed on weaned animals to assess possible long-term effects of the rearing practice.ResultsTotal VFA concentrations were higher in mothered lambs at 2 months of age, while artificially-reared lambs had lower average daily gain, a more degraded sanitary status and lower serum IgG concentration in the early growth phase. Metataxonomic analysis revealed higher richness of bacterial and eukaryote populations in mothered vs. artificially-reared lambs in both Rumen and Feces. Beta diversity analysis indicated an evolution of rumen and fecal bacterial communities in mothered lambs with age, not observed in artificially-reared lambs. Important functional microorganisms such as the cellulolytic bacterium Fibrobacter succinogenes and rumen protozoa did not establish correctly before weaning in artificially-reared lambs. Enterobacteriaceae and Escherichia coli were dominant in the fecal microbiota of mothered lambs, but main E. coli virulence genes were not found differential between the two groups, suggesting they are commensal bacteria which could exert a protective effect against pathogens. The fecal microbiota of artificially-reared lambs had a high proportion of lactic acid bacteria taxa. No difference was observed in mucosa gene expression in the two lamb groups after weaning.ConclusionsThe rearing mode influences gastrointestinal microbiota and health-associated parameters in offspring in early life: rumen maturation was impaired in artificially-reared lambs which also presented altered sanitary status and higher risk of gut dysbiosis. The first month of age is thus a critical period where the gastrointestinal tract environment and microbiota are particularly unstable and special care should be taken in the management of artificially fed newborn ruminants.

Growth performance and ruminal fermentation of lambs supplemented with calcium propionate: A meta-analysis

This study aimed to evaluate the effects of dietary calcium propionate (CaPr) supplementation on growth performance and ruminal fermentation of lambs using a meta-analytic method. The data used were obtained from 10 peer-reviewed publications. The effect size was assessed using weighted mean differences (WMD) between CaPr supplementation and control treatments. Dietary supplementation with CaPr did not affect (P > 0.05) dry matter intake, hot carcass yield, Longissimus dorsi muscle area, rumen pH, and butyrate concentration, but it increased average daily gain (WMD = 0.012 kg/d; P = 0.022), and ruminal concentration of total volatile fatty acids (WMD = 6.633 mM; P = 0.022) and propionate (WMD = 4.443 mol /100 mol; P < 0.001). In contrast, a lower feed conversion ratio (WMD = −0.288 kg/kg; P = 0.029) and ruminal acetate concentration (WMD = −3.319 mol/100 mol; P < 0.001) were observed in response to CaPr supplementation. In conclusion, the dietary inclusion of calcium propionate can be used as a nutritional strategy to improve growth rate and ruminal fermentation in fattening lambs.

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 emissionsmore effectively than Ziziphus nummularia leaves, and the energy saved was transformed into higher body weight gain and improved feed conversion ratio.

Effect of genotype and environment on the productive and survivability traits of lambs under a community-based management system

The aim of this study was to evaluate the growth and survival of local and Dorper crossbred lambs managed under a community-based management system, using data collected between 2012 and 2021. The fixed effects considered were breed, location, sex, type of birth, parity, season, and year of birth. The results revealed that Dorper crossbred lambs consistently weighed and gained more than local lambs (p<0.0001) at all ages and that environmental factors such as location, sex, type of birth, parity, season, and year of birth had considerable influence on most growth traits at all ages. The mean birth weight of local, low-grade, and high-grade Dorper crossbred lambs were 2.12 ± 0.04, 2.94 ± 0.03, and 3.08 ± 0.03 kg, respectively. The corresponding pre-weaning daily gain was 89.12 ± 1.85, 112.16 ± 1.38, and 117.98 ± 1.71 g/day, respectively. The post-weaning body weight gain at 90-180 days for the same groups was 32.6 ± 2.16, 46.85 ± 1.62, and 45.93 ± 1.98 g/day, respectively. Dorper crossbred lambs exhibited a bodyweight advantage of up to 45%, 31%, 34%, and 28% over local lambs at birth, 3, 6, and 12 months of age, respectively. Lambs born in the dry season had the lowest weaning (p<0.0001) and six-month (p = 0.0098) weight compared to those born in the rainy seasons. Lamb genotype didn’t have a significant influence on the survival of lambs at all ages, but most environmental factors influenced survivability. Lambs born to ewes in their 5th parity and above had a mortality risk of 0.51 times higher than those born to ewes in their 1st to 4th parity at the age of 6- months. Year of lambing affected lamb pre-weaning (χ2 = 0.0003) and post-weaning (χ2 = 0.0001) survival. Compared to the base year 2021, lambs born in 2017 and 2018 had a higher risk of mortality at 6-month (10.1 and 15.9 times, respectively) than those born in 2021. Season of birth also significantly (χ2 <0.001) affected lamb survivability, with lambs born in the dry season, having a higher mortality risk at weaning (0.46 times) and yearling (0.66 times). Lambs with a birth weight of 2 kg and below had a 2.3 times higher survival risk at 6-months compared to lambs born with 3 kg and above. In conclusion, Dorper crossbred lambs can be considered to improve lamb growth performance and produce fast-growing lambs. However, the study recommends further research to validate the crossbreeding program (considering the influential production environment, research on supplementation for lambs in the dry-season, adjusting the mating season, and the economic feasibility of crossbreeding are suggested).

Comparison of the Effect of using Chemical Buffer and Acid-Consuming Bacteria on Digestibility and Fermentation, Growth Performance and Meat Quality of Lambs Fed with High Concentrate Diets

Comparison of the Effect of using Chemical Buffer and Acid-Consuming Bacteria on Digestibility and Fermentation, Growth Performance and Meat Quality of Lambs Fed with High Concentrate Diets

Replacing ground Rhodes grass hay with soyhulls in the pelleted diet: effects on ingestive behavior, nutrient digestibility, blood metabolites, growth performance, and economic viability of intensive fattening Lohi lambs.

This study aimed to evaluate the effects of replacing soyhulls (SH) for ground Rhodes grass hay (RGH) in a pelleted diet on ingestive behavior, digestibility, blood metabolites, growth performance, and economic viability of fattening Lohi lambs. A total of thirty male lambs (age: 5months; body weight 20.4 ± 0.24kg) were allotted to one of the three diets (n = 10 lambs/diet) under a completely randomized design. The diets were with 25% RGH inclusion (control), replacing 15% RGH with 15% SH as a fiber source (SH-15), and containing only 25% SH inclusion on a dry basis (SH-25). Ingestive behavior parameters like time spent (min/day), bouts frequency (number/day), and bout length (min/bout) for feeding, drinking, rumination, chewing, standing, and lying were not influenced (P > 0.05) by replacing RGH with SH. The dry matter (DM) and neutral detergent fiber (NDF) chewing rate, rumination rate, and feeding efficiency were also not changed (P > 0.05) by dietary treatments, whereas total dry matter and NDF intakes, and their rumination efficiencies were lower (P < 0.05) for the SH-25 than for the rest of the treatments. The digestibility of NDF and acid detergent fiber (ADF) was higher (P < 0.05) for the SH-25 than for the rest of the treatments. The concentrations of blood metabolites like glucose, blood nitrogen, and cholesterol were not changed (P > 0.05) among the treatment groups. Similarly, performance parameters like dry matter intake, initial and final body weight, average daily gain, and feed conversion ratio were similar (P > 0.05) across the treatments. However, the incidence of loose fecal consistency was higher (P < 0.05) for SH-25 than for the control. The values of economic efficiency were better for SH-25-fed lambs than those fed the rest of the treatments. Based on the results, substituting SH for RGH in a pelleted diet improved the digestibility of fiber fractions, and economics without affecting the growth performance, and blood metabolites of fattening lambs. However, lower rumination efficiency and loos fecal consistency are evidencing less effectiveness of SH fiber.

Finisher lamb growth and rumen fermentation responses to the plane of nutrition and naturally occurring coccidiosis.

The objective of the present study was to investigate the interaction of plane of nutrition and naturally occurring coccidiosis on finisher lamb growth performance, FAMACHA score, and rumen volatile fatty acid profile. The study included 30 Suffolk, Dorset or Suffolk x Dorset lambs and were divided into 2 groups based on their initial body weight and assigned to 2 feeding groups differing in dietary energy intake to create lambs representing divergent growth curves due to differing nutritional management. Lambs with naturally occurring coccidiosis and healthy lambs were present in both feeding groups making a 2 × 2 factorial arrangement of treatments, (a) high plane of nutrition (HPN) lambs with no clinical coccidiosis diagnosis (HPNH), (b) HPN lambs with clinical coccidiosis (HPNC), (c) low plane of nutrition (LPN) lambs with no clinical coccidiosis diagnosis (LPNH), (d) LPN lambs with clinical coccidiosis (LPNC). Body weight and FAMACHA scores were recorded once every 2 weeks. On d 65 of feeding, lambs were slaughtered, and rumen fluid samples were collected and analyzed for volatile fatty acid concentrations. All response variables were analyzed statistically using a linear mixed effects model with fixed effects for plane of nutrition, health status, and a random effect for initial body weight nested within the pen. The total and average weight gain were not associated with planes of nutrition, health status, or the interaction. Health status had an impact on FAMACHA© score (P = 0.047) and concentration of isobutyrate (P = 0.037) and tended to affect total VFA (P = 0.085) and acetate (P = 0.071) concentrations. The interaction between the plane of nutrition and the health status tended to affect butyrate concentration (P = 0.058). These data support the conclusion that coccidiosis infection impacted on rumen fermentation in a manner independent of the plane of nutrition; however, the translation of these rumen level impacts did not translate to the production responses.

Comparative energy value of cooked grease recovered from rinse-trap water lines used as dietary fat source for feedlot lambs

The objective of this experiment was to compare the effects of dietary supplementation with cooking grease recovered from rinse-trap water lines (rinse-trap grease; RTG) versus conventional supplemental fats (tallow; TL, and yellow grease; YG) on 84-d growth performance, dietary energy, and carcass traits of feedlot lambs. Forty-eight Pelibuey × Katahdin lambs (27.7 ± 3.4 kg) were assigned in a randomized complete block design to evaluate: 1) basal diet without supplemental fat (Control); 2) 4% TL; 3) 4% YG, and 4) 4% RTG. Supplemental fats replaced maize in the control diet. Rinse-trap grease contained greater moisture (16.5 vs 0.92%) and impurities (3.6 vs 0.56%), and less total fatty acid (64.90 vs 89.60%) than that of conventional fats (TL and YG). Daily weight gain and gain efficiency were similar for control and RTG supplemental lambs, whereas ADG and gain efficiency were greater for lambs fed conventional fats than control or RTG-supplemented lambs. Both dietary net energy (NE) as well as ratio of observed-to-expected dietary NE were 4% greater for lambs supplemented with conventional fats vs RTG. Supplemental fat increased fat deposition but did not affect any other carcass measures or non-fat visceral mass. Estimated NE value for RTG was 57% of the average NE value (6.11 Mcal/kg) of tested conventional fats. Supplementation with RTG does not affect diet acceptability, and accordingly, is a suitable energy source for feedlot lambs. However, due to its lower total fatty acid content, its energy value is much lower than conventional supplemental fats.