Lamb Production:grazing management, breeding policy and parasite control

Internal parasitic infection can pose major health problems in young livestock and this is particularly so in the context of lambs in organic production systems. In the context of sheep production on an organic farm the challenge to control parasite infection is especially difficult in situations where crop production is absent or a minor element of the whole farm system. Our investigations, to date at Athenry, have concerned an exploration of lamb production in an all-grass farming setting with particular attention being paid to the breeds employed and the seasonal patterns of gastrointestinal parasite challenge. This flock (about 110 ewes plus replacements) is wintered indoors and lambs in early March each year

Plane of nutrition during the rearing phase for replacement ewes of four genotypes: II - effects on performance during first pregnancy and to weaning, and of their progeny

peer-reviewedPlane of nutrition (PN) offered to ewe replacements during the rearing phase (8 to 17 months) and first pregnancy may affect reproductive and progeny performance when replacements are joined at ~19 months. The effects of PN offered to spring-born ewe replacements during their first winter (winter_1), second summer (summer_2) and subsequent winter (mid and late pregnancy; winter_2) were evaluated, over 3 consecutive years, using 287 ewe lambs of four genotypes: Charmoise×Scottish Blackface (C×SBF), Belclare×SBF (Bel×SBF), Belclare (Bel) and Belclare×SBF (heterozygous for a gene, either FecGH or FecXG mutations, that increases ovulation rate: BelMG×SBF). Ewe lambs were offered, daily, a deferred-grazed herbage allowance (HA) of either 0.75 or 1.75 kg dry matter during winter_1. During summer_2 the replacements were set-stocked to maintain sward heights of 4 or 6 cm. Ewes were housed during mid and late pregnancy (winter_2) and offered either medium or high-feed-value grass silage, thus yielding a 2×2×2 factorial design. Increasing HA during winter_1 and residual sward height during summer_2 increased ewe BW post joining (P0.05) on number of lambs reared. Increasing HA during winter_1 increased lamb BW at birth (P<0.05) and reduced carcass fat score (P<0.05). There was a significant interaction between PN offered during winter_1 and summer_2 for average daily gain (ADG) from birth to 5 weeks (P<0.01) and from 5 to 10 weeks (P<0.05): progeny of replacements that experienced either a high or low PN throughout the rearing phase had lower ADG than lambs born to the replacements that experienced a low PN only during winter_1 or summer_2. Increasing PN during winter_2 increased ewe BW (P<0.001), lamb BW at birth (P<0.001) and weaning (P<0.05) and reduced the proportion of ewes that failed to lamb (P<0.01). Ewe genotype had a significant (P<0.001) effect on litter size (1.48 to 2.45), number of lambs reared, lamb BW at birth and weaning, lamb ADG and age at slaughter. It is concluded that, among the nutrition treatments examined, increasing PN during mid and late pregnancy had the greatest effect on ewe and progeny performance. Although increasing PN offered during winter_1 increased lamb birth BW, PN offered during summer_2 had no effect on lamb performance. There were no significant interactions between PN and ewe genotype

Plane of nutrition during the rearing phase for replacement ewes of four genotypes: I – effects on growth and development, and on ovulation rate at first joining

peer-reviewedPlane of nutrition (PN) offered to ewe replacements during the rearing phase (8 to 17 months) affects BW at joining and may affect reproductive performance when joined at ~19 months. The effects of PN offered to ewe replacements during their first winter (winter_1) and second summer (summer_2) were evaluated over 3 consecutive years, using 287 spring-born ewe lambs, representing four genotypes (Belclare (Bel), Charmoise×Scottish Blackface (C×SBF), Bel×SBF (Bel×SBF), Bel×SBF that were heterozygous either FecGH or FecXG mutations that increase ovulation rate (OR) (BelMG×SBF)). During extended (deferred) grazing in winter_1 (November to March) the lambs were offered herbage DM allowances (HA) of 0.75 (L) or 1.75 (H) kg/day. During summer_2 (March to August) the replacements were set stocked to maintain sward heights of 4 (L) or 6 (H) cm, thus yielding a 2×2 factorial design for the nutrition treatments (71 to 73 animals/treatment). Increasing HA during winter_1, and residual sward height during summer_2, increased (P0.05) on OR. Mean BW at joining was 53.3, 56.8, 56.6 and 61.7 (SEM 0.74) kg for ewes offered the LL, LH, HL and HH treatments, respectively. Mean OR of C×SBF and BelMG×SBF differed (P0.05) between the PN offered during winter_1 and summer_2, or PN and ewe genotype for BW at joining or OR. LMs, either at 7, 12 or 17 months of age, are useful predictors of BW at joining

Investigation of Intestinal Atresia in a Jersey Sire Family

PEER-REVIEWEDIntestinal atresia is a congenital defect resulting in calf mortality within a few days of birth. This study focuses on two half-sibling Jersey sires who were identified as having a high proportion of their progeny exhibiting atresia from a longitudinal study of 39 dairy herds over an 8 year period. The objective of this study was to investigate the genetic cause of intestinal atresia within this family. Phased high-density genotypes of the two half-sibling sires were used to identify if common haplotypes were inherited by all affected animals. Whether or not the paternal haplotype that was inherited by the affected animal at a given locus deviated from the expectation was tested. A total of 16 SNPs were significantly overrepresented, 14 located in one region on chromosome 14 and the remaining 2 located in one region on chromosome 26

Effects of arformoterol twice daily, tiotropium once daily, and their combination in patients with COPD

Current guidelines support using in combination more than one class of long-acting bronchodilator for COPD patients whose symptoms are not controlled by mono-therapy. This 2-week, multi-center (34 sites), randomized, modified-blind, parallel group study evaluated the efficacy and safety of concomitant treatment with nebulized arformoterol (the formoterol(R,R)-isomer) BID and tiotropium DPI QD. COPD patients (mean FEV(1) 1.37L, 45.4% predicted) were randomized to receive mono-therapy (either arformoterol 15microg BID [n=76] or tiotropium 18microg QD [n=80]), or combined therapy (sequential dosing of arformoterol 15microg BID and tiotropium 18microg QD [n=78]). Changes in pulmonary function, dyspnea, and rescue levalbuterol use were evaluated, as were safety outcomes. Mean FEV(1)AUC(0-24) (the primary endpoint) improved similarly from baseline for arformoterol (0.10L) and tiotropium (0.08L) treatment groups and greater for the combined therapy group (0.22L; all p-values <0.005). Peak FEV(1), peak FVC, 24-h trough FEV(1), and inspiratory capacity also improved similarly for the mono-therapies and greatest for the combined therapy. Dyspnea (mean transition dyspnea index) improved similarly for arformoterol (+2.3) and tiotropium (+1.8) and greatest with combined therapy (+3.1; p-values <0.05). Levalbuterol use decreased for all treatment groups (range -1.8 to -2.5 actuations/day). All treatments had similar frequency of adverse events. In this study, the combination of nebulized arformoterol 15microg BID plus tiotropium 18microg DPI QD was the most effective in improving pulmonary function and disease symptoms. Mono-therapy improvement with arformoterol or tiotropium was similar. All three treatments were well tolerated

Can ChatGPT outperform a neurosurgical trainee? A prospective comparative study

Purpose This study aimed to compare the performance of ChatGPT, a large language model (LLM), with human neurosurgical applicants in a neurosurgical national selection interview, to assess the potential of artificial intelligence (AI) and LLMs in healthcare and provide insights into their integration into the field. Methods In a prospective comparative study, a set of neurosurgical national selection-style interview questions were asked to eight human participants and ChatGPT in an online interview. All participants were doctors currently practicing in the UK who had applied for a neurosurgical National Training Number. Interviews were recorded, anonymised, and scored by three neurosurgical consultants with experience as interviewers for national selection. Answers provided by ChatGPT were used as a template for a virtual interview. Interview transcripts were subsequently scored by neurosurgical consultants using criteria utilised in real national selection interviews. Overall interview score and subdomain scores were compared between human participants and ChatGPT. Results For overall score, ChatGPT fell behind six human competitors and did not achieve a mean score higher than any individuals who achieved training positions. Several factors, including factual inaccuracies and deviations from expected structure and style may have contributed to ChatGPT's underperformance. Conclusions LLMs such as ChatGPT have huge potential for integration in healthcare. However, this study emphasises the need for further development to address limitations and challenges. While LLMs have not surpassed human performance yet, collaboration between humans and AI systems holds promise for the future of healthcare

Selection for improved reproductive performance of native sheep

Meeting: Small Ruminants Research and Development in the Near East, 2-4 Nov. 1988, Cairo, EGIn IDL-298

Effects of reseeding with perennial ryegrass, chicory or tyfon in pure stands or mixtures on lamb performance postweaning

Many producers reseed old pasture (OP) with the objective of improving lamb performance. Old pasture was reseeded with perennial ryegrass plus white clover (RGC), RGC plus chicory (CG), RGC plus tyfon (TG), chicory (C), or tyfon (T) to generate five treatments. In addition, a contiguous block of OP was included in the study for comparative purposes. Lambs (n = 286) were assigned to one of the five treatments plus the section of OP from just after weaning until slaughter. Grazing commenced 45 days after the desiccation of OP for reseeding. All lambs were managed by rotational grazing and drafted for slaughter at a specified target BW. No concentrate supplement was offered during the study. For the RGC, CG, TG, C and T treatments and the OP section, the average herbage NDF concentrations were 524, 473, 402, 352, 256 and 565 (SE 15.4) g/kg DM; total grazing days were 5 213, 4 005, 4 466, 2 262, 3 496 and 3 677 (SE 629.3); BW gain to slaughter was 211, 175, 205, 211, 199 and 203 (SE 9.5) g/day; days to slaughter were 91, 100, 84, 86, 78 and 88 (SE 4.8). Compared to RGC, the C, T, CG and TG treatments had lower herbage NDF concentrations (P  0.05) for BW gain or days to slaughter. Chicory yielded significantly fewer (P < 0.05) grazing days, but tended to give a higher (P < 0.06) carcass weight than RGC. It is concluded that neither reseeding OP with RGC, including either C or T with RGC as a multispecies sward, nor growing pure stands of C or T increased (P < 0.05) lamb BW gain from weaning to slaughter or reduced days to slaughter

Effects of joining at 7 months, and ewe genotype, on the performance of ewes to 19 months of age and that of their progeny to slaughter

peer-reviewedTwo ways of reducing the cost of replacements are increasing litter size and number of litters produced; thus, the total weight of lamb carcass output per ewe lifetime. The effects of ewe genotype on the performance of ewes lambing at 1 year and of their progeny to slaughter, and the effect of age at first joining (7 or 19 months) on BW at ~19 months and survival to joining at 19 months were evaluated over two consecutive years, using 460 ewe lambs from three genotypes: Belclare (Bel), Suffolk × Belclare (Suf × Bel) and ≥ 75% Suffolk ancestry (Suf75). Lambs from the three genotypes were at a similar proportion of mature BW and half of the lambs, within genotype, were allocated to be joined for the first time at 7 or 19 months. The ewe lambs were managed in a grass-based rotational-grazing system, except when housed from December to March on a grass silage-based diet. Belclare ewes had larger litters (P  0.05) on lamb mortality (born dead, total mortality to weaning), lambing assistance, number of ewes that failed to lamb, or on ewe survival to 19 months of age. Increasing ewe BW at joining increased the probability (P < 0.001) of rearing at least one lamb and this effect was consistent across genotypes. There were significant relationships (P < 0.001) between ewe BW at lambing and lamb BW at birth and at weaning of 0.053 (SE 0.0089) kg and 0.29 (SE 0.049) kg, respectively. Ewes that lambed at 1 year were 2 kg lighter (P < 0.001) at 19 months of age and had a smaller body size (P < 0.01) relative to those not joined. It is concluded that ewe genotype had a significant effect on number of lambs reared, and thus lamb carcass output. Whilst lambing at 1 year reduced BW by 2 kg when joined at 19 months, it did not affect ewe survival to that stage