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Present experiment was conducted with the objective to study the effect of water restriction and rehydration on haemato-biochemical, hormonal and enzymatic activity of indigenous sheep under intensive production system. Eighteen farm born unshorn hoggets (25-30 kg) of Patanwadi and Marwari breeds were randomly distributed in to three treatment groups on the basis of body weight comprising of six in each group viz., T1 Control (ad libitum water), T2 (20% water restriction) and T3 (40% water restriction). The experiment was conducted in summer season for 30 days i.e. 28 days of water restriction and 2 days of rehydration phase. The feed, in accordance with physiological and production needs of the animals, was offered twice a day (09:00 and 18:00 hrs). Water intake was recorded thrice a day (09:00, 14:00 and 19:00 hrs) and blood samplings was done on day 0, day 28 and after 48 hrs of rehydration. The values of haemoglobin, were significantly decreased, while, serum urea, uric acid, alkaline phosphatase, creatinine phosphokinase, cortisol, triiodothyronine and aldosterone were significantly (p < 0.05) increased in water restricted groups of animals on 28th day, with significant improvement in values on 48 hrs of rehydration in most of the traits. However, the decrease in glucose was non-significant between 0 and 28 days and no change was noted in thyroxin levels due to water restriction or rehydration. It indicated that water restriction resulted significant changes in blood variables of hoggets. Blood variables recovered significantly after 48 hr of rehydration, but the serum cortisol, urea, AKP, CPK and T3 values till did not attain normalcy, thereby demonstrating that the animals did not recover completely from dehydration stress. [ABSTRACT FROM AUTHOR]

The reproductive performance of ewe hoggets is poorer than that of mature-age ewes due to production of fewer lambs with poorer survival. Scant data are available on the risk factors for, and causes of, the mortality for lambs born to ewe hoggets, the impact of ewe deaths on lamb loss, and the causes of death for lambs born to ewe hoggets vs. mature-age ewes lambing in the same circumstances. In this study, 297 lambs born to 1142 ewe hoggets were necropsied along with 273 lambs born to 1050 mature-age ewes. Low lamb birthweight, multiple litter size, and increasing ewe hogget average daily gain from breeding to late pregnancy were risk factors for lamb mortality. The most common cause of mortality for lambs born to ewe hoggets was stillbirth and the risk factors for stillbirth were similar to those for lamb mortality generally. Approximately 11% of ewe hoggets’ lamb deaths were due to the death of the dam. Causes of mortality differed between lambs born to ewe hoggets vs. those born to mature-age ewes. Management practices to increase ewe hogget lambs’ birthweights (particularly those from multiple litters) and supervision of ewe hoggets at lambing time are recommended.

The contribution of abortions to the overall mortality of lambs born to maiden (primiparous) ewes in Australia remains unclear. This cohort study aimed to quantify abortion and lamb mortality for ewe lambs and maiden Merino two-tooth ewes. Lamb mortality from pregnancy scanning to marking were determined for 19 ewe lamb and 11 Merino two-tooth ewe flocks across southern Australia. Average lamb mortality from scanning to marking was 35.8% (range 14.3–71.1%) for the ewe lambs and 29.4% (range 19.7–52.7%) for the two-tooth ewes. Mid-pregnancy abortion was detected in 5.7% of ewes (range 0–50%) in the ewe lamb flocks and 0.9% of ewes (range 0–4.4%) in the two-tooth ewe flocks. Mid-pregnancy abortion affecting ≥2% of ewes was observed in 6/19 ewe lamb flocks and 2/11 two-tooth ewe flocks. Lamb mortality from birth to marking represented the greatest contributor to foetal and lamb mortality after scanning, but mid-pregnancy abortion was an important contributor to lamb mortality in some ewe lamb flocks. Variability between the flocks indicates scope to improve the overall reproductive performance for maiden ewes by reducing foetal and lamb losses. Addressing mid-pregnancy abortion may improve the reproductive performance in some flocks.

Ewe wastage is the combination of on-farm mortality and premature culling. Internationally, there is limited research on actual wastage incidence and causes in commercial sheep flocks. To the authors’ knowledge, this is the first study that reports both lifetime wastage and detailed annual wastage in a sample of commercial New Zealand flocks. This study utilized data collected from 13,142 ewes from four cohorts on three commercial New Zealand farms (Farm A 2010-born, Farm A 2011-born, Farm B, Farm C), during the period 2011–2017, as they aged from replacement hoggets to 6-year-old ewes (Farm A and Farm B) or 3-year-old ewes (Farm C). Data collection visits occurred at three or four key management times each year, namely pre-mating, pregnancy diagnosis, pre-lambing and weaning. At each visit, body condition score (BCS) was assessed and any ewes that were culled or had died on farm were recorded. As this was a lifetime study, each ewe was assigned an outcome and corresponding ‘exit age’. By the end of the study, all ewes that had exited their respective flocks, were classified as either prematurely culled, or dead/missing, or if still in the flock, as censored, and either the exact date or interval in which they exited the flock was recorded. Semi-parametric competing risk (premature culling vs. dead/missing), interval-censored survival models were developed to: 1. describe the association between hogget reproductive outcomes and risk of subsequent wastage, and 2. assess pre-mating BCS as a predictor of wastage in that production year. Of the 13,142 enrolled ewes, 50.4% exited their respective flocks due to premature culling and 40.0% due to on-farm dead/missing, giving a total of 90.4% that exited due to wastage. Annual mortality incidence ranged from 3.5 to 40.2%. As a hogget, wastage incidence ranged from 7.6 to 45.4%. Pregnancy or rearing a lamb as a hogget did not increase risk of subsequent wastage. In all years, pre-mating BCS was a predictor of ewe wastage, with odds of wastage lower with increasing BCS. Therefore, farmers should focus on improving pre-mating BCS to 3.5/5.0 by assessing ewe BCS at weaning, allowing poorer-BCS ewes to be managed to gain BCS before re-breeding.

Increasing the number of lambs with high-quality meat weaned per ewe, optimised for each farm system, is a key mechanism to improve the overall efficiency of sheep production. Lambing hoggets (yearlings) has long been identified as one way to improve efficiency, with the potential to maintain or increase production within the same environmental footprint. However the adoption of hogget lambing in New Zealand remains low due to both negative perception of the practice among farmers, and poor reproductive performance in hoggets. In this review we describe the processes contributing to reproductive success in hoggets, outline the research that underpins industry guidelines for lambing hoggets, and identify knowledge gaps and potential for improvement in hogget lambing efficiency. [ABSTRACT FROM PUBLISHER]

Bu araştırmada 7 Karayaka uzun kuyruklu ve 7 Gıcık yağlı kuyruklu erkek toklu kullanılmıştır. Toklulara tüm arpa ve yonca samanı ad libitum olarak verilmiştir. Deneme 28 gün sürmüştür. Gıcık tokluların günlük 139.3 g ve toplam canlı ağırlık artışları 3.90 kg ile yemden yaralanma oranları 10.32 Karayakalarınkinden sırasıyla 43.60 g, 1.22 kg ve 26.58 yüksek bulunmuştur. Toplam plazma kolesterolü Gıcıklarda 13.56, Karayakalarda ise, 18.37 mg/dL bulunmuştur. Gıcıklarda HDL, LDL, VLDL düzeyleri sırasıyla 14.80, 49, 5.80 mg/dL; Karayakalarda ise, sırasıyla 15.40, 43.20 ve 4.60 mg/dL olarak bulunmuştur. Grupların toplam plazma kolesterolü ve lipoprotein HDL, LDL, VLDL düzeyleri arasında önemli farklılıklara rastlanılmamıştır.

Abstract: Ewe lambs have the ability to be successfully bred at 7–9 months of age. Breeding ewe lambs has a number of advantages including increased profitability and lifetime reproductive performance. However due to low and variable reproductive performance and the potential for negative effects on future performance, most ewe lambs are not bred. This review compares the differences in reproductive performance between ewe lambs and mature ewes. In addition, it summarises the known effects of ewe lamb breeding on lifetime performance. It also focuses on factors affecting the success of ewe lamb breeding. Lastly, it outlines the optimal management of the ewe lamb to the weaning of her first lamb and to maximise her lifetime performance. [Copyright &y& Elsevier]

The reported study involved mature ewes that had either been presented for breeding and had lambed as a hogget (MP), had been presented for breeding as a hogget but did not become pregnant (MNP) or were not presented for breeding as a hogget (NM). Their subsequent performance as mature ewes was examined. Although breeding as a hogget reduced (P <0.05) two-tooth mating live weight and condition score in subsequent years, the differences were either smaller or not present at all (P>0.05). Breeding as a hogget increased (P<0.05) the number of foetuses per ewe lifetime (8.2±0.08, 7.0±0.13 and 7.1±0.12 for MP, MNP and NM respectively) but did not alter ewe (P>0.05) longevity. These results indicate that hogget breeding can be used as a management option to improve lifetime reproductive performance. [ABSTRACT FROM AUTHOR]

The effect of liveweight at the start of the breeding period and liveweight gain of hoggets during the breeding period and in pregnancy on breeding performance, pregnancy loss and liveweight and the performance of their progeny were examined. Two groups of hoggets with an average liveweight of 36 kg (denoted L) and 42 kg (denoted H) at the start of the breeding period were allocated to either medium or ad lib levels of herbage during pregnancy, resulting in four treatment groups (L-med, L-ad lib, H-med and H-ad lib). Liveweight changes of the medium and ad lib treatment hoggets were 153 and 208 g/day, respectively. Starting liveweight had no effect (P>0.05) on the overall breeding performance, pregnancy rate, foetuses per hogget joined, number of hoggets lambing or pregnancy loss. Lambs born to the H treatment hoggets were heavier (P<0.05) at weaning than those born to L hoggets (21.69 and 20.11 kg, respectively). More (P<0.05) medium treatment hoggets were not bred during the 22 day breeding period than ad lib treatment hoggets (14 and 4%, respectively). The results indicate that heavy hoggets at the commencement of the breeding period increase the progeny liveweight at the time of weaning and increase hogget weaning weight, but with no effect on reproductive performance. On the other hand, ensuring hoggets are increasing in weight by more than 200 g/day during breeding and pregnancy results in fewer hoggets not bred and hoggets heavier at the time of weaning. Farmers should therefore ensure that adequate herbage is available so that hoggets can achieve these targets. [ABSTRACT FROM AUTHOR]

Simple Summary: Pre-weaning lamb deaths limit the production performance from ewes that are bred as hoggets (at 6–9 months of age). The present study aimed to investigate factors that are associated with increased likelihood of lamb death and the cause of that death, in lambs and in ewe hoggets over the lambing period. This was also compared to rates in mature-age ewes and their lambs. Lambs with low birthweights or that were born as twins were more likely to die, as were lambs whose dams had greater live weight changes during pregnancy. Ewes deaths during the lambing period accounted for approximately 11% of lamb deaths. The most common cause of hogget lamb deaths was stillbirth (lamb born dead) but this was an uncommon cause of death in lambs born to mature-age ewes. Management tools to increase lamb birthweights, and supervision of ewe hoggets at lambing time, are recommended. The reproductive performance of ewe hoggets is poorer than that of mature-age ewes due to production of fewer lambs with poorer survival. Scant data are available on the risk factors for, and causes of, the mortality for lambs born to ewe hoggets, the impact of ewe deaths on lamb loss, and the causes of death for lambs born to ewe hoggets vs. mature-age ewes lambing in the same circumstances. In this study, 297 lambs born to 1142 ewe hoggets were necropsied along with 273 lambs born to 1050 mature-age ewes. Low lamb birthweight, multiple litter size, and increasing ewe hogget average daily gain from breeding to late pregnancy were risk factors for lamb mortality. The most common cause of mortality for lambs born to ewe hoggets was stillbirth and the risk factors for stillbirth were similar to those for lamb mortality generally. Approximately 11% of ewe hoggets' lamb deaths were due to the death of the dam. Causes of mortality differed between lambs born to ewe hoggets vs. those born to mature-age ewes. Management practices to increase ewe hogget lambs' birthweights (particularly those from multiple litters) and supervision of ewe hoggets at lambing time are recommended. [ABSTRACT FROM AUTHOR]

Abstract: This study was undertaken to determine if breeding ewe lambs (hoggets) would influence subsequent two-year-old (two-tooth) ewe liveweight and reproductive performance and their lamb''s performance to weaning. Two-tooth Romney ewes that had been bred and lambed as a hogget (n =505) were compared with those of 196 ewes that were bred as a hogget but did not lamb and 235 ewes that were not presented for breeding as a hogget. Hogget lambing resulted in reduced (P <0.05) two-tooth liveweight and body condition score at breeding although still present this liveweight difference was reduced by two-tooth lamb weaning. Two-tooth ewes that had previously lambed as a hogget had greater (P <0.05) returns to service rates and lower (P <0.05) fecundity (multiple-bearing/two-tooth bred) than those that were bred for the first time. Two-tooth lamb liveweights were unaffected by hogget lambing. These results show that hogget lambing had a small negative effect on subsequent two-tooth reproductive performance. This was most likely caused by reduced liveweight at two-tooth breeding and indicates that farmers need to ensure management practices are in place to reduce the impact of hogget lambing on two-tooth liveweight. [Copyright &y& Elsevier]

The effect of nutrition during pregnancy in hoggets has not been thoroughly examined under pastoral conditions in New Zealand. The aim of the present study was to determine if a high liveweight gain in pregnancy reduced hogget reproductive performance, and to determine the effect of this regimen on the liveweight of the hogget and her progeny in lactation. Mated, synchronised hoggets, from day 5 of pregnancy, were managed to either: gain 100 g/day in total liveweight throughout pregnancy (Medium), gain 100 g/day until day 36 of pregnancy followed by 200 g/day for the remainder of pregnancy (Medium/high) or to gain 200 g/day throughout pregnancy (high). Actual average daily liveweight gains for Medium and high group hoggets were 134.3 and 223.7 g/day respectively. Average liveweight gains of Medium/high hoggets for the two periods were 103.3 and 237.2 g/day respectively. Significantly (P < 0.05) fewer high hoggets held to service compared to their Medium and Medium/ high counterparts (54.5 versus 78.2 versus 83.6% respectively). However, pregnancy scanning showed that there was no difference between groups in percentage pregnant (48.2 versus 44.5 versus 50.9% respectively), nor were there any differences in the percentage which lambed (44.6 versus 41.2 versus 48.3% respectively). Within birthrank there was no effect of hogget treatment on lamb birthweight. In late lactation, not only were lambs born to high hoggets significantly (P < 0.05) heavier than those born to Medium hoggets (17.69 versus 15.88 kg), the hoggets themselves were heavier (54.68 versus 47.80 kg respectively). These findings suggest that farmers should not avoid relatively high liveweight gains in pregnancy with hoggets. In fact, they may be beneficial. [ABSTRACT FROM AUTHOR]

Simple Summary: The reproductive efficiency of ewes in their first breeding season (maiden ewes) can be inconsistent and disappointing. The frequency of abortion and its relative contribution to lamb losses in maiden ewe flocks in Australia has not been well studied. This study measured abortion and lamb mortality occurring between pregnancy diagnosis (scanning) and lamb marking in 30 flocks of maiden ewes on Australian sheep farms. The study included flocks of ewe lambs that had lambed for the first time at approximately one-year-old (n = 19) and two-tooth ewes that had lambed for the first time at two-years-old (n = 11). Abortion was detected in 14/19 flocks of ewe lambs and 6/11 flocks of two-tooth ewes using repeated scans. On average 5.7% of ewe lambs and 0.9% of two-tooth ewes aborted; however, abortion rates between flocks ranged from 0–50% for ewe lambs and 0–4.4% for two-tooth ewes. Lamb mortality from birth to marking represented the greatest contributor to overall lamb mortality occurring after pregnancy scanning but abortions were an important contributor to the overall losses in some ewe lamb flocks. This study highlights the variability in reproductive performance for maiden ewes and indicates that addressing losses due to abortion may improve reproductive performance in some ewe lamb flocks. The contribution of abortions to the overall mortality of lambs born to maiden (primiparous) ewes in Australia remains unclear. This cohort study aimed to quantify abortion and lamb mortality for ewe lambs and maiden Merino two-tooth ewes. Lamb mortality from pregnancy scanning to marking were determined for 19 ewe lamb and 11 Merino two-tooth ewe flocks across southern Australia. Average lamb mortality from scanning to marking was 35.8% (range 14.3–71.1%) for the ewe lambs and 29.4% (range 19.7–52.7%) for the two-tooth ewes. Mid-pregnancy abortion was detected in 5.7% of ewes (range 0–50%) in the ewe lamb flocks and 0.9% of ewes (range 0–4.4%) in the two-tooth ewe flocks. Mid-pregnancy abortion affecting ≥2% of ewes was observed in 6/19 ewe lamb flocks and 2/11 two-tooth ewe flocks. Lamb mortality from birth to marking represented the greatest contributor to foetal and lamb mortality after scanning, but mid-pregnancy abortion was an important contributor to lamb mortality in some ewe lamb flocks. Variability between the flocks indicates scope to improve the overall reproductive performance for maiden ewes by reducing foetal and lamb losses. Addressing mid-pregnancy abortion may improve the reproductive performance in some flocks. [ABSTRACT FROM AUTHOR]

Simple Summary: Ewe wastage is the combination of on-farm mortality and premature culling. Increased wastage results in a reduction in flock productivity and profitability, yet internationally, there is limited research on actual wastage incidence and causes in commercial flocks. This study reports both lifetime wastage and detailed annual wastage for 13,142 ewes from four cohorts on three commercial New Zealand farms. This study also describes the relationship between ewe pre-mating body condition score and wastage. Of the 13,142 enrolled ewes, 50.4% and 40.0% exited their respective flocks due to premature culling and on-farm dead/missing, respectively. Annual mortality incidence ranged from 3.5 to 40.2%. Wastage as a hogget was identified as an area in which improvements can be made to reduce overall wastage. Pre-mating body condition score was a predictor of wastage, with ewes with greater pre-mating body condition score having lower odds of wastage due to both premature culling and mortality. Therefore, farmers should focus on improving the body condition score of their ewes prior to breeding. Ewe wastage is the combination of on-farm mortality and premature culling. Internationally, there is limited research on actual wastage incidence and causes in commercial sheep flocks. To the authors' knowledge, this is the first study that reports both lifetime wastage and detailed annual wastage in a sample of commercial New Zealand flocks. This study utilized data collected from 13,142 ewes from four cohorts on three commercial New Zealand farms (Farm A 2010-born, Farm A 2011-born, Farm B, Farm C), during the period 2011–2017, as they aged from replacement hoggets to 6-year-old ewes (Farm A and Farm B) or 3-year-old ewes (Farm C). Data collection visits occurred at three or four key management times each year, namely pre-mating, pregnancy diagnosis, pre-lambing and weaning. At each visit, body condition score (BCS) was assessed and any ewes that were culled or had died on farm were recorded. As this was a lifetime study, each ewe was assigned an outcome and corresponding 'exit age'. By the end of the study, all ewes that had exited their respective flocks, were classified as either prematurely culled, or dead/missing, or if still in the flock, as censored, and either the exact date or interval in which they exited the flock was recorded. Semi-parametric competing risk (premature culling vs. dead/missing), interval-censored survival models were developed to: 1. describe the association between hogget reproductive outcomes and risk of subsequent wastage, and 2. assess pre-mating BCS as a predictor of wastage in that production year. Of the 13,142 enrolled ewes, 50.4% exited their respective flocks due to premature culling and 40.0% due to on-farm dead/missing, giving a total of 90.4% that exited due to wastage. Annual mortality incidence ranged from 3.5 to 40.2%. As a hogget, wastage incidence ranged from 7.6 to 45.4%. Pregnancy or rearing a lamb as a hogget did not increase risk of subsequent wastage. In all years, pre-mating BCS was a predictor of ewe wastage, with odds of wastage lower with increasing BCS. Therefore, farmers should focus on improving pre-mating BCS to 3.5/5.0 by assessing ewe BCS at weaning, allowing poorer-BCS ewes to be managed to gain BCS before re-breeding. [ABSTRACT FROM AUTHOR]

• The sensory quality of lamb meat was in general higher than that of hogget meat. • The meat of NS hogget may better fulfill out-of-season fresh meat supply. • The meat from the NWS breed was generally of lower eating quality than from the NS. This study compared the meat sensory profile of lambs (5 months old) and hoggets (17 months old) from two sheep breeds, Norwegian White Sheep (NWS) and Norwegian Spel (NS). The loin (left and right) samples (M longissimus thoracis et lumborum) from 50 carcasses were analysed for 23 sensory attributes by a trained sensory panel using quantitative descriptive analysis evaluated on an unstructured line scale from 1 (lowest intensity) to 9 (highest intensity). There was an effect (P < 0.05) of animal age on the attributes: odour (fried roasted, sheep and intensity), flavour (fried roasted, gamey, sheep, rancid and liver), hardness, tenderness, fatness, and coarse fibre structural unit. The loin muscles of lambs were scored significantly lower compared to that from the hoggets in all the sensory attributes except rancid odour, flavour, and juiciness. Sheep odour, hardness, and coarse fibre intensity differed between breeds (P < 0.05) – the NWS breed obtained a higher score than the NS breed. Meat from lambs of both breeds and the hogget NS breed was similar in tenderness while that from the NWS hoggets was scored lower by the panel. For the attribute hardness, lambs and hoggets were similar within each breed, except the NS hoggets were similar to NWS lambs. There was an interaction between animal age and breed (P < 0.05) for the fried roasted and gamey odour. The results indicate that animal age has a lower impact on eating quality for the NS breed than for the NWS breed. In the Norwegian scenario, the NS hoggets appear more suitable for supplying fresh out-of-season meat. Results should be confirmed with a larger sample size of both breeds. [ABSTRACT FROM AUTHOR]