Age Of Lambs Research Articles

Effects of Breeding Practices on Reproductive Efficiency of Ewes and Fattening Performance of Lambs

In this study, the data obtained by questionnaire from small ruminant farms in Tekkeköy district of Samsun province were evaluated. Among the enterprises in the study, 50% of them breed Karayaka sheep, and 33.4% of them breed Bafra sheep. It was determined that 95.8% of the farmers applied flushing before ram siring, 83.3% of the farmers applied feed supplements to the ewes after birth, 95.8% of the farmers applied additional vitamin supplements to the lambs, and 83.3% of the farmers used salt-containing licking stones for the lambs. In the study, internal and external parasites were applied to the lambs to be fattened in all of the farms, and all of them were not released to pasture until sale. Winter lambs were fattened in 91.7% of the farms. The average age of the breeders is 50, and 1.08 rams are sired in an average year in the farms. The average age of lambs sent to slaughter is 4 months, and the average carcass weight at slaughter is 19.15 kg. Feed supplementation to the ewes after birth and application of salt-containing licking stones to the lambs had a positive effect on the average carcass weight of the fattened lambs. In this study, it was determined that winter lambs were preferred more than summer lambs. According to this result, by fattening winter lambs in this period when there is no pasture opportunity, both seasonal meat needs can be met, and it provides the opportunity to sell at high prices in the winter period. In this case, the breeder will earn more income.

Spatiotemporal Expression and Haplotypes Identification of KRT84 Gene and Their Association with Wool Traits in Gansu Alpine Fine-Wool Sheep.

Keratin (K) is a major protein component of hair and is involved in hair growth and development. In this study, we analysed the expression, localization, and polymorphism of the K84 gene (KRT84) in Gansu Alpine Fine-wool sheep using immunofluorescence, RT-qPCR, and PARMS (penta-primer amplification refractory mutation system). Haplotypes of KRT84 were also constructed and their relationship with wool traits analysed. It was revealed that KRT84 was highly expressed in hair follicles, including the inner root sheath, outer root sheath, and hair medulla and at all six lamb ages investigated from 1 to 270 days of age. Three SNPs were detected in KRT84 exon 1, and they formed three haplotypes (named H1, H2, and H3) and six genotypes. Analyses revealed an association between haplotype combinations (diplotypes) and the mean fibre curvature, mean staple length, mean staple strength, mean fibre diameter, the coefficient of variation of fibre diameter, and comfort factor for these sheep. These results suggest that KRT84 is of importance in determining several key traits in Gansu Alpine Fine-wool sheep and that the gene could possibly be used as a genetic marker for wool trait selection in these sheep.

Longitudinal Study of Antibiotic Resistance of Staphylococci from Cases of Subclinical Mastitis in Sheep in Greece: Incidence and Risk Factors.

The present paper extends a previous publication on a field study of subclinical mastitis in sheep and focuses on the following laboratory characteristics of the staphylococcal isolates: antibiotic resistance and association with biofilm formation. The specific objectives of the present study were (a) to describe the incidence of isolation of antibiotic-resistant staphylococci from cases of mastitis throughout the milking period in dairy sheep flocks and (b) to identify relevant risk factors, which would contribute to the sustainable control of the infection. Staphylococcal isolates from subclinical mastitis were evaluated for antibiotic resistance to 18 antibiotics. Antibiotic resistance was detected in 57 of the 179 staphylococcal isolates from subclinical mastitis (31.8%). Resistance was recorded against 11 antibiotics, most often against ampicillin (63.2% of resistant isolates), penicillin (63.2%) and tetracycline (47.4%). Isolates resistant to ampicillin and penicillin were recovered in all 12 farms. Twenty-one multidrug-resistant isolates (11.7%) were also recovered. The incidence risk of isolation of staphylococci resistant to at least one (any) antibiotic throughout the study period was 23.8%. The incidence risk of isolation of staphylococci resistant to oxacillin was 5.0%; that of isolation of multidrug-resistant staphylococci was 8.8%. With regard to increased incidence risk of isolation of staphylococci resistant to at least one (any) antibiotic and increased incidence risk of isolation of staphylococci resistant to oxacillin, the omission of anti-staphylococcal mastitis vaccination of ewes emerged as a risk factor. With regard to increased incidence risk of isolation of multidrug-resistant staphylococci, the following variables emerged as risk factors: (a) higher number of antibiotics used on the farm for the treatment of mastitis and (b) younger age of lambs taken away from their dam. Most biofilm-forming antibiotic-resistant staphylococci were recovered from farms where anti-staphylococcal mastitis vaccination was not applied (55.9% versus 44.1% from farms where anti-staphylococcal mastitis vaccination was applied).

Combining sheep and beef cattle in a pasture-based system minorly influenced muscle and fat colour and dorsal fat firmness but increased fat skatole content in lambs.

A recent long-term system-level experiment, using grassland-based organic systems established as separate farmlets, showed that combining sheep and beef cattle within a mixed (MIX) system promoted self-sufficient production of grass-fed meat and improved economic and environmental performance in the sheep enterprise compared to a sheep-only (SH) system. In the present study, we used all male lambs produced over the first year in this experiment to evaluate the effect of this farming practice on some lamb carcass and meat sensory quality traits. Lambing took place at the end of February and lambs were pasture-fed from 1month of age on average until slaughter, unless they were not ready for slaughter at 3-4weeks before the start of the mating period in October, in which case they were finished indoors on a concentrate-based diet. All MIX lambs (n=33) were finished at pasture. One SH lamb (out of a total of 85) had to be finished indoors with a concentrate-based diet. MIX lambs had a higher growth rate than SH lambs (P<0.001), resulting in a lower lamb age at slaughter in MIX than in SH (150 vs 173days, P<0.001). Carcass weight and degree of fatness, kidney fat weight and dorsal fat thickness did not differ between systems. Kidney fat skatole concentration was higher in MIX than in SH (median value reaching 0.15µg/g liquid fat and 0.11µg/g liquid fat in MIX and SH, respectively, P<0.05). This was most likely due to MIX lambs being slaughtered at a younger age and therefore eating younger grass. There were minor differences between MIX and SH lambs in dorsal fat firmness and in colour coordinates of longissimus thoracis et lumborum muscle. We conclude that while combining sheep and beef cattle within a mixed system offers advantages in terms of self-sufficient production of grass-fed meat and system economic and environmental performance, it could come at a cost to lamb flavour.

Determination of the ovine ovarian reserve during the prenatal and neonatal periods

Objective: To determine the ovine ovarian histomorphology and follicular staging at various age periods in Awassi breed. Methods: Ovaries were collected from prenatal fetuses [gestational age (95±5) days], neonatal (day 0), and prepubertal ewe lambs (two and four months of age); each age group included six animals. Ovaries (n=12, each group) were dissected and processed for hematoxylin and eosin staining. Stained sections (n=24, each group) were imaged and utilized for histomorphology assessment, follicle measurement, and classification. Results: Prenatal ovaries were mainly enriched with primordial follicles accompanied by a lower proportion of primary follicles. In addition to primordial and primary follicles, neonatal ovaries demonstrated a proportion of centrally located multilayered and antral follicles. In comparison with neonatal ovaries, the proportion of multilayered and antral follicles was significantly higher in the ovaries of two-month-old lambs; conversely, the proportion of peripherally situated primordial follicles dramatically declined compared to that of earlier age of lamb. Although there was no statistical variation in the sizes of primordial follicles across groups, the mean diameter of the primary follicle in the prenatal ovaries was substantially smaller than in postnatal ovaries. Compared to the neonatal ovaries, the size of the multilayered and antral follicles in the prepubertal ovaries was substantially larger. Conclusions: The earliest follicular developmental stages were established prenatally whereas the advanced growth stages started in the neonatal period and greatly increased in the prepubertal period.

Impact of polyacrylamide supplementation on intake, nutrient digestion and growth of lambs.

This study was conducted to evaluate the effect of polyacrylamide (PAM) supplementation on the intake, digestion, weight gain, metabolism and growth of lambs. A total of ten 30 days old male small-tailed Han lambs with a body weight of 7.7±0.5 kg were divided into two equal groups (n = 5 each) and fed a basal diet or diet supplemented with 2.0 g of PAM per kg diet. The duration of the experiment was 210 days and experimental diets were fed ad libitum throughout the experimental period. Voluntary feed intake (VFI) was measured on daily basis, while body weight was measured on every ten days of the experiment.Two digestive and metabolic trials were conducted at the lamb's age of 95 to 103 days (Trial 1) and at the age of 210 to 218 days (Trial 2). At the end of experiment, all lambs were slaughtered to determine carcass characteristics. Results of the current study showed that supplementation of PAM in the diet of lambs increased the VFI and daily body gain by 14.4% (P < 0.05) and 15.2% (P < 0.01), respectively. In Trial 1, PAM supplementation in the diet increased the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), cellulose, energy, and nitrogen retention by 7.9%, 5.4%, 6.4%, 9.6%, 4.3% and 30.3% (P < 0.01), respectively, and in Trial 2, PAM supplementation in the diet increased the digestibility of DM, OM, CP, cellulose, energy, and nitrogen retention by 9.3%, 7.9%, 7.7%, 11.6%, 6.9% and 38.5% (P < 0.01), respectively. Results of carcass parameter explored that supplementation of PAM in the diet increased the carcass, net meat and lean meat weights by 24.5%, 25.5%, and 30.6% (P < 0.01), respectively, however, PAM supplementation in the diet did not influence the contents of DM, OM, or CP in fresh liver, leg muscle, and rumen tissue; in addition, the CP contents in the Longissimus dorsi muscle was decreased by the supplementation of PAM in the diet. In summary, supplementation of 2.0 g of PAM per kg diet increased the VFI, nutrient digestibility, nitrogen retention, and carcass yield of lambs.

Desempenho zootécnico de cordeiros Dorper x Santa Inês criados em diferentes sistemas de produção

Abstract The objective of this work was to compare the zootechnical performance of Dorper x Santa Inês crossbred lambs finished in grazing systems on Megathyrsus maximus Aruana cultivar pasture, with and without shading, and in a feedlot. Twenty-four non-castrated lambs were used in a completely randomized experimental design, with the three following treatments with eight replicates each: 'Aruana' pasture without shading + supplement; 'Aruana' pasture with shading + supplement; and feedlot, with diet containing ryegrass hay and concentrate at a 20:80 ratio. The treatments did not influence lamb age at slaughter, birth weight, leg compactness, true yield, and main cut yield, except that of breast tip + flank that was lower for the pasture with shading. However, average daily gain, body condition score, live weight at slaughter, carcass compactness index, cold carcass and empty body weights, and cold carcass yield differed between treatments, showing higher values in the feedlot. Termination in the feedlot increases the zootechnical performance of Dorper x Santa Inês sheep and favors a lower age at slaughter, as well as a greater weight of the main commercial cuts, but not their yield.

Is the inclusion of carob (Ceratonia siliqua L.) pulp in the concentrate of weaned light lambs worth it?

This study aimed at evaluating the effects of dietary carob (Ceratonia siliqua L.) pulp, a by-product of the fruit processing industry, on light lamb performances, time budget behaviour, coefficients of total tract apparent digestibility (CTTAD) and blood metabolites. A total of 144 crossbred lambs with 41 ± 5.5 days of age were monitored in two consecutive batches. They were housed in groups of 6 lambs (3 females and 3 males) balanced according to weaning body-weight and assigned to one of three isoenergetic and isoproteic concentrate-based diets: C0 (without carob pulp), C15 (150 g/kg of carob pulp) and C30 (300 g/kg of carob pulp). At 50, 65 and 80 days of age, feed, faeces and blood samples were collected, and behaviour was recorded. The type of concentrate did not have effect on lamb growth and concentrate intake (P > 0.05). However, the concentrate feed conversion ratio (FCR) was higher for C15 and C30 compared to C0 (P < 0.05). The time budget behaviours were not affected by diets (P > 0.05). The time spent lying resting and standing static increased throughout the fattening period (P < 0.05), but self-grooming, feeding, exploration, movement and positive social interactions decreased with age (P < 0.05). Regarding the CTTAD of dry matter (DM), organic matter (OM) and crude protein (CP), it was noted that C30 had the lowest digestibility of these nutrients with respect to C0 and C15 (P < 0.05). Furthermore, the total condensed tannins (CT) content in faeces was higher in C30 compared to C0 and C15 (P < 0.05). The age of lambs affected the CTTAD of DM, OM, CP and phosphorus, which were lower at 50 days than in the rest of control days (P < 0.05). Blood metabolites were not affected by experimental diets (P > 0.05). However, urea concentrations increased significantly from 50 to 65 days of age, while glucose decreased concomitantly (P < 0.05). In conclusion, dietary carob pulp inclusion up to 300 g/kg does not negatively affect animal daily gains, daily activity budgets and metabolic nutritional status, but reduces diet digestibility and increases the concentrate FCR. Although a carob pulp inclusion of up to 150 g/kg in the energy-rich concentrate-based diet for weaned light lambs increases the concentrate FCR while keeping the daily gain, this dietary strategy would be a good trade-off between animal performances and circular economy principles.

PSIII-7 Evaluation of Maternal Selenium Supplementation and Plane of Nutrition During Gestation on the Neonatal Fc Receptor (Fcrn) in Lamb Intestinal Tissue

Abstract Maternal selenium (Se) supply and plane of nutrition alter morbidity and mortality in lambs as well as 24-h serum IgG. The neonatal Fc receptor (FcRn) transports IgG across mucosal surfaces; however, its role in intestinal protection in the lamb is unknown. Additionally, the effects of maternal nutrition on offspring FcRn abundance has not been reported. The objective of this study was to evaluate intestinal FcRn abundance in lambs born from ewes fed differing levels of nutrition and Se. Intestinal tissues from two experiments (EXP1 n=71; EXP2 n=80) were used. Both experiments utilized a 2x3 factorial design. Main effects included Se supplementation [adequate (9.5 or 11.5 μg/kg of BW in EXP1 or EXP2; respectively) or high, (81.1 or 77.0 μg/kg of BW in EXP1 or EXP2; respectively)] and plane of nutrition [60% (RES), 100% (CON), or 140% (HIGH) of requirements for both experiments]. Lambs were raised to 57 d or 21 d (EXP1 and EXP2; respectively). Intestinal tissues were collected and fixed in 10% NBF prior to paraffin embedding. Cross-sections were stained for FcRn and counterstained with DAPI. Areas of tissue cross-sections were captured with Plan-Apochromat 20x/0.8 NA lens using the tiling module of Zeiss. Images were analyzed using ImagePro Premiere software. Relative fluorescence within areas of interest was used as an indicator of FcRn receptor abundance. Data were analyzed using the general linear model procedure of SAS. Maternal nutrition tended (P≤0.07) to affect lamb intestinal FcRn abundance with CON having higher abundance compared to HIGH or RES (EXP1). There was no effect of maternal nutrition in EXP2 or maternal Se supplementation on intestinal FcRn abundance in lambs from either experiment (P≥0.56). These data show that maternal nutrition may influence offspring FcRn abundance and that further studies examining the contribution of lamb age are needed.

Efficacy of decoquinate in pelleted feed in case of eimeriosis in lambs

Eimeriosis of sheep reduces the profitability of the production of wool, leather, meat, and milk, which causes substantial damage to the sheep industry, and therefore requires the introduction of effective means of prevention and treatment of animals from this infestation. The purpose of this study was to establish the efficacy of decoquinate in granular feed in case of lamb eimeriosis. As a result of coproscopic studies according to DSTU 5079 2008 “Veterinary medicine. Methods of laboratory diagnosis of eimerioses” determined the extent of invasion of lambs by oocysts of various Eimeria species, namely E. arloingi – 41%, E. crandallis – 29%, E. intricate – 15%, E. faurei – 15%, which are registered in animals of separate farms of the Cherkasy region. Clinical symptoms of eimeriosis are observed in young animals from the age of one month and are characterized by anaemia of visible mucous membranes, diarrhoea, depression of the general condition, weakness, and predominantly acute course of invasion with high mortality. The manifestation of clinical symptoms of the disease depends on many factors, namely the age of lambs, the sanitary situation on the farm, changes in feed fattening programs, stressful situations that arise due to the movement of sheep to other premises or weaning lambs from ewes. In older lambs, as a rule, the disease has a chronic and asymptomatic course. In such animals, Eimeria oocysts are excreted in faeces in much smaller quantities than in one-month-old lambs during an acute course of infection. The maximum values of invasion extensiveness (100%) and invasion intensiveness (12,000 oocysts in 1 g of faeces) were found in two-month-old lambs. Invasion in the digestive canal of these animals worsens the absorption of feed nutrients, which contributes to a decrease in the average daily weight gain (on average 155.3 g/day), which increases with treatment of animals with decoquinate (on average 185.7 g/day). In general, the use of decoquinate in sick lambs at a dose of 1 mg/kg of body weight for 28 days shows prominent therapeutic and preventive effectiveness. Therewith, extensefficiency is 90%, and parasite carrier is observed only in 10% of animals. Therefore, for the effective treatment of lambs of distinct age groups, the decoquinate preparation can be recommended, which is especially important for farms with intensive rearing of young sheep

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.

Analysis of genetic parameters and genetic trends for early growth and reproductive traits of Doyogena sheep managed under community-based breeding program

This study aims to estimate genetic parameters and genetic trends for early growth and reproductive traits of Doyogena sheep. Data used in the study were collected over 6 years (2013–2018). Studied traits were birth weight (BWT), weaning weight (WWT), 6-month weight (SMWT), average daily gains from birth to weaning (ADG0-3), average daily gains from weaning to 6-month age (ADG3-6), average daily gain from birth to 6-month age (ADG0-6), litter size (LS), lambing interval (LI), age at first lambing (AFL), and annual reproductive rate (ARR). (Co) variance components and genetic parameters were estimated using restricted maximum likelihood (REML). The analyses were carried out using WOMBAT program. Univariate analysis was applied to estimate genetic parameters. Six different animal models were fitted by including or excluding maternal effects. The direct heritability estimates for BWT, WWT, SMWT, ADG0-3, ADG3-6 and ADG0-6 were 0.33 ± 0.06, 0.31 ± 0.06, 0.14 ± 0.06, 0.13 ± 0.04, 0.11 ± 0.07, and 0.02 ± 0.05 respectively. Direct heritability for LS, LI, and AFL were 0.28 ± 0.12, 0.20 ± 0.5, and 0.001 ± 0.3, respectively. The maternal heritability estimates for BWT, WWT, and LS were 0.24 ± 0.12, 0.60 ± 0.07, and 0.24 ± 0.08, respectively. The genetic correlation between BWT with WWT and BWT with SMWT were 0.21 ± 0.07 and 0.21 ± 0.09, respectively. Genetic progress for most of the studied traits has shown promising improvements. Thus, continuation of selection, therefore, suggested for more improvements in the performance of Doyogena sheep. Direct heritability estimates decrease as lamb age increases and selection based on earlier body weight will be more efficient.

Optimization of Slaughter Age of Jamuna Basin Lamb Based on Carcass Traits and Meat Quality

The aim of this study was to identify optimum slaughter age on carcass traits and meat quality of Jamuna basin lambs. Thirty lambs were divided into three age groups like T1 (6 months), T2 (9 months) and T3 (12 months) having ten lambs of each treatment. Parameters studied were carcass traits, proximate component (DM, CP, EE, and Ash), physicochemical (Ultimate pH, cooked pH, cooking loss, drip loss, water holding capacity-WHC), sensory attributes (color, flavor, tenderness, juiciness, overall acceptability) and instrumental color values (L*, a* and b*). Hot carcass weight and dressing% were found significantly (p&lt;0.001) higher in T3 than T1 and T2 treatments. Edible by products namely viscera, head, leg, pluck, neck, shoulder, rack, loin, kidney, heart, liver, lungs and shank from three treatments were found significant effect (p&lt;0.001). Inedible by products viz. blood, skin and spleen were found significantly higher (p&lt;0.001) with the advancement of age. Dry matter (DM) of T2 and T3 were found significantly lower (p&lt;0.001) than T1 treatment. Crude protein (CP) and ether extract (EE) were significantly increased (p&lt;0.001) of advancement of age of lambs. Drip loss of T2 was found significantly lower and WHC of T2 was significantly (p&lt;0.001) higher than other two treatments. Cooking loss and ultimate pH of T3 were significantly (p&lt;0.001) lower than other two treatments. Color, tenderness, juiciness and overall acceptability were significantly differed (p&lt;0.001) and flavor was significantly differed (p&lt;0.001). The instrumental color values L* decreased whereas a* and b* and chroma values were significantly (p&lt;0.05) increased with the advancement of age of lambs. The saturation index was significantly (p&lt;0.001) higher in 6- and 12-months age than 9 months of age. It is revealed from the study that 12 months of slaughter age showed better in terms of productive and meat quality traits. Therefore, 12 months of age may be recommended as optimum slaughter age for Jamuna basin lambs. SAARC J. Agric., 19(2): 257-270 (2021)

Maternal deprivation and milk replacement affect the integrity of gray and white matter in the developing lamb brain.

The psychoendocrine evaluation of lamb development has demonstrated that maternal deprivation and milk replacement alters health, behavior, and endocrine profiles. While lambs are able to discriminate familiar and non-familiar conspecifics (mother or lamb), only lambs reared with their mother develop such clear social discrimination or preference. Lambs reared without mother display no preference for a specific lamb from its own group. Differences in exploratory and emotional behaviors between mother-reared and mother-deprived lambs have also been reported. As these behavioural abilities are supported by the brain, we hypothesize that rearing with maternal deprivation and milk replacement leads to altered brain development and maturation. To test this hypothesis, we examined brain morphometric and microstructural variables extracted from in vivo T1-weighted and diffusion-weighted magnetic resonance images acquired longitudinally (1 week, 1.5 months, and 4.5 months of age) in mother-reared and mother-deprived lambs. From the morphometric variables the caudate nuclei volume was found to be smaller for mother-deprived than for mother-reared lambs. T1-weighted signal intensity and radial diffusivity were higher for mother-deprived than for mother-reared lambs in both the white and gray matters. The fractional anisotropy of the white matter was lower for mother-deprived than for mother-reared lambs. Based on these morphometric and microstructural characteristics we conclude that maternal deprivation delays and affects lamb brain growth and maturation.

Responses to melatonin of 2 breeds of dairy ewes in early lactation under autumn photoperiod conditions

A total of 72 dairy ewes of 2 breeds (MN, Manchega, 72.4 ± 1.9 kg of body weight, n = 36; LC, Lacaune, 77.7 ± 2.3 kg of body weight; n = 36) were used to evaluate the lactational effects of melatonin implants in early lactation and under the short-day photoperiod conditions of autumn (experiment was centered on the winter solstice). Ewes lambed in autumn and were penned indoors in 12 balanced groups of 6 ewes by breed, body weight, age, and number of lambs, and randomly assigned to a 2 × 2 × 3 factorial design (treatment × breed × replicate). Ewes suckled their lambs for 28 d. Treatments were (1) melatonin (MEL), which received 1 subcutaneous implant of melatonin (18 mg/ewe) in the ear base at 35 ± 1 d (1 wk after lamb weaning), and (2) control, which did not receive any treatment. Ewes were fed ad libitum a total mixed ration (forage:concentrate, 60:40) and machine milked twice daily. Daily milk yield was automatically recorded from d 29 to 105 of lactation and sampled every 2 wk for composition. Jugular blood was sampled for plasma hormone analyses at 30, 50, 80, 110, and 124 d of lactation. Body reserves were assessed every 2 wk. Feed intake was measured by pen during 3 separated periods after the start of the treatments (wk 2 to 3, wk 6 to 7, and wk 10 to 11). Feed intake, and milk yield and composition varied by breed, but no MEL effects were detected on dry matter intake, milk yield, milk composition, or fat and protein standardized milk in either breed. As a result of the unique composition of the implants and the variable body weights of the ewes, the MEL treatment dose (on average, 0.24 mg/kg of body weight) was 6.8% greater in the MN (lighter) than in the LC (heavier) ewes. Plasmatic melatonin markedly increased in the MEL-treated ewes (on average, 111%), but despite the amount of MEL used, the MN responded greatly compared with the LC ewes (150 vs. 63%, respectively). No differences in basal plasmatic melatonin were detected between breeds (6.4 ± 1.1 pg/mL, on average), indicating the greater responsiveness to the implants of the lighter MN ewes. Plasmatic prolactin tended to decrease in the MEL-treated ewes (-35%, on average), but the effect was significant only in the MN ewes (-54%), in agreement with their greater response to MEL. No effects of MEL treatment were detected on plasmatic IGF-I in either breed. Moreover, body reserves did not vary by effect of MEL treatment or breed throughout the experiment. In conclusion, the use of exogenous melatonin as MEL implants, together with the endogenous melatonin naturally produced under short-day photoperiod conditions, had no effects on the early-lactation performances of dairy sheep, despite their breed and level of production.

Dynamic change of fungal community in the gastrointestinal tract of growing lambs

Although fungal communities in the gastrointestinal tract have a significant role in animal health and performance, their dynamics within the tract are not well known. Thus, this study investigated fungal community dynamics in the rumen and rectum of lambs from birth to 4 mon of age by using IT1S rDNA sequencing technology together with the RandomForest approach to determine age-related changes in the fungal ecology. The results indicated that gastrointestinal fungal community composition, diversity, and abundance altered (P<0.05) with the increasing age of the lambs. Two phyla, Ascomycota and Basidiomycota, dominated the samples. Similarity within age groups of the rumen fungi increased sharply after 45 days of age, while the similarity increased (P<0.05) significantly after 60 days of age in the rectum. The age-related genera, Acremonium, Microascus, Valsonectria, Myrmecridium, Scopulariopsis, Myrothecium, Saccharomyces, and Stephanonectria, were presented in both ruminal and rectal communities, and their changes in relative abundance were consistent at both sites. The principal coordinates analysis showed significant differences (P<0.05) between the fungal communities in the rumen and rectum. Our findings demonstrate that both the age of lambs and the gastrointestinal tract region can affect the composition of these fungal communities, and this provides new insight and directions for future studies in this research area.

Effect of Breeding Heavier Romney Ewe Lambs at Seven Months of Age on Lamb Production and Efficiency over Their First Three Breeding Seasons.

Simple SummaryThis experiment examined the impact of breeding heavier ewe lambs on lamb production and the ability of a ewe to produce a high number and heavier lambs (i.e., efficiency) over the first three breeding seasons. Two groups of ewe lambs were bred at seven months of age at an average live weight of either 47.9 ± 0.36 kg (n = 135) or 44.9 ± 0.49 kg (n = 135). Ewe live weight, number of lambs born and weaned, and lamb live weights were recorded, and ewe efficiency was calculated for each ewe. The weight and number of lambs at weaning over the three-year period did not differ between treatments, however, when data were pooled, heavier ewe lambs at breeding had a greater number and lamb weaning weight over the three-year period. Breeding heavier ewe lambs had no effect on ewe efficiency. There was a positive relationship between ewe lamb breeding live weight and their mature weight. These results suggest that breeding heavier ewe lambs increased the total lamb production over the three-year period, however, it had no effect on ewe efficiency. Before final recommendations can be made, ewe lifetime performance and longevity of heavier ewe lambs at breeding are required.This experiment examined the effect of breeding heavier ewe lambs on lamb production and their efficiency over their first three breeding seasons. Two groups of ewe lambs were bred at seven months of age at an average pre-breeding live weight of either 47.9 ± 0.36 kg (heavy; n = 135) or 44.9 ± 0.49 kg (control; n = 135). Ewe live weight, number of lambs born and weaned, and lamb live weight were recorded until 39 months of age, and efficiency was calculated for each ewe. Although the number and lamb weaning weight did not differ between treatments over three years, when data were pooled, heavier ewe lambs at breeding weaned a greater number of lambs over the three-year period. The total lamb weaning weight over the three-year period increased by 2% for each additional kilogram at ewe lamb breeding. Breeding heavier ewe lambs had no effect on efficiency. These results suggest that although breeding heavier ewe lambs had a positive effect on lamb production over the three-year period, it had no effect on efficiency. Before final recommendations can be made, lifetime performance and longevity to five years of age of heavier ewe lambs at breeding are required.

Modeling the growth curve of Muzaffarnagari lambs from India

Body weights (BW) of 2,611 Muzaffarnagari lambs at birth and 3, 6, 9, and 12 months of age were used to compare five alternative growth curves. Four three-parameter functions (Brody, von Bertalanffy, Gompertz, and logistic) and the four-parameter Richards function were fit for each lamb. Estimates of the asymptotic final BW (A), a maturing-rate parameter (k), and the degree of maturity at birth (u0) = BW/A were estimated for each function. A shape parameter (m) was included in the Richards function and used to identify the degree of maturity (u) at the point of inflection of the growth curve (uI). Among three-parameter functions, the Brody function had the smallest pooled residual sum of squares (RSS) across all lambs and the smallest RSS for 56% of individual lambs. For the Brody function, the growth rate is maximum at birth and declines continuously as animals age. In comparison with the Brody function, fitting the Richards function with a variable inflection point did not significantly reduce RSS. Comparisons of Brody and Richards functions indicated that the Richards function converged to a Brody function for 17% of the lambs. The predicted growth rate was maximum at an average uI of 0.26 for the Richards function and at an average of u0 = 0.10 for the Brody function. Parameters k and m interacted to define the maturing rate in the Richards function, and the predicted age at u= 0.50 (t50) was proposed to measure growth efficiency. Correlations between estimates of A, u0, and t50 for the Brody and Richards functions were all 0.89, confirming limited benefit from fitting the Richards function. For the Brody function, correlations among estimates of A, k, and u0 were modest (-0.59 to 0.39). Use of these parameter estimates in selection to modify the growth curve would be relatively straightforward. Correlations among A, k, and u0 from the Richards function were also modest (-0.60 to 0.27), but the correlation between k and uI was 0.82. Selection to modify the Richards parameters would therefore be more challenging, and the Richards function likely over-parameterized the growth curve. We therefore concluded that the Brody function was the most appropriate growth function to describe BW changes from birth to 1 year of age in Muzaffarnagari lambs.

EFFECT OF CHLORELLA MICROHYDROGEN SUSPENSION ON PRODUCTIVITY AND GROWTH INTENSITY OF LAMBS

The work was performed in Rozdilnyanske LLC of Rozdilnyansky district of Odessa region. For research, 5 groups of suckling ewes of the Gypsy breed were formed with 10 heads each, one of the groups was a control. Groups were formed by the method of analogue groups taking into account the breed, age in lambs, live weight, which was 50 kg. Chlorella microalgae suspension was fed to ewes in the first 20 days of lactation, in the amount of 3; 5; 7; 9 ml per 1 kg of live weight. Growth intensity, external parameters, and hematological and biochemical composition of blood were determined in newborn lambs at the age of 20 days according to generally accepted methods. It was found that feeding a suspension of chlorella microalgae to lactating ewes at the rate of 3, 5, 7, 9 ml per 1 kg of live weight increases milk productivity by 2.6-4.4 times and live weight of the offspring by 58.8-96.9%, compared to ewes that did not use chlorella microalgae suspension. With an increase in the amount of chlorella microalgae suspension in the diet of lactating ewes, the absolute increase in live weight of their offspring increases by 2.4-4.5 times. The average daily increase in live weight of lambs ranged from 199 g to 339.5 g

Supplementing lycopene combined with corn improves circulating IgG concentration in pregnant ewes and their lambs.

Lycopene (C40H56, a non-provitamin A carotenoid) is a lipid-soluble pigment and a natural antioxidant with immunomodulatory activities. The objective of this study was to investigate the effects of lycopene with or without corn supplementation on circulating hormones, white blood cells, immunoglobulin G (IgG) concentrations, quality of colostrum in pregnant ewes, and IgG concentrations in newborn lambs. Forty multiparous single-bearing ewes (68 ± 8.4kg body weight, mean ± SD) were fed in four groups of CONTROL (fed a basal diet (BD)), CORN (BD + 300g/day corn), LYCOP(BD + 100mg/day lycopene), and LYCORN (BD + 300g/day corn + 100mg/day lycopene). The quantity and chemical composition of colostrum were determined. Blood samples were taken from ewes right after lambing and from lambs at 3 and 24h of age. Results showed that corn supplementation increased (P < 0.05) udder volume, the quantity of colostrum, as well as percentage of lactose, and protein in colostrum. Corn-supplemented ewes had higher circulating glucose, prolactin, and estradiol but lower urea and progesterone than control ewes. The ratio of progesterone to estradiol (P4/E2) in the blood of pregnant ewes decreased (P < 0.05) after corn supplementation. Lycopene, irrespective of corn, increased the percentage of lymphocyte cells in pregnant ewes. Both corn and lycopene increased circulating IgG concentrations and subsequently increased the total IgG in colostrum at 6h post-partum. Lycopene significantly elevated the circulating IgG at 24h of age in lambs. In conclusion, lycopene along with corn supplementation additively increased concentrations of IgG in the blood of ewes and in the colostrum, which resulted in an enhancement of passive immune transfer to the newborn lambs.