Pre Weaning Research Articles

Selection Practices of Bonga Sheep Reared in Southern Ethiopia

The study was conducted to assess the traits traditionally used to select the Bonga sheep reared in Southern Ethiopia. The breed was included for improvement under the community based breeding program (CBBP) launched in the year 2009. The results are based on the data collected from the project between 2009 till 2012. The findings are based on focus group discussions with the community elders who have been rearing the Bonga sheep for more than 20 years. The present findings are based on information obtained from 50% of the total respondents who were involved in CBBP. The Bonga sheep is a mutton type breed and the ewes are moderately prolific. In the past this breed of sheep were bartered to settle legal disputes and were traded against household commodities.. However, over the years (and also after the intervention of CBBP) the sheep have been selected for their body weight as well as for their distribution in many parts of Ethiopia The respondents selected the lambs at both pre weaning and post weaning stages. Traditionally the traits of rams are selected based on their body length, canon circumference, broad face, enlarged thyroid, while for the ewes, traits prolificacy, skin thickness and pelvic width are determining characters. Fat tail and brown coat color were preferred irrespective of the sexes in trait selection. The ram lambs selected for breeding purpose are locally known as “Dookoo”. These rams are selected based on some predetermined phenotypic traits and are initially selected at preweaning stage and further, again at the post weaning stage. These rams are preferentially cared and are provided with supplementary feed and comfortable housing.

Performance evaluation of Soviet Chinchilla and Californian White rabbit breeds in tropical climatic conditions of India

Study was conducted to evaluate the performance of Soviet Chinchilla and Californian White rabbit breeds maintained in tropical environment at rabbit research station, Hyderabad, Telangana. Data generated on total of 1364 bunnies, 701 belongings to the Soviet Chinchilla born in 122 litters and 663 bunnies of Californian White born in 124 litters during the period from 2012 to 2015 were utilized to examine the various productive performance traits. The overall least-squares mean litter size and litter weight was 5.52 ± 0.16 and 264.75 ± 7.86 at birth and 3.56 ± 0.17 and 1439.67 ± 72.55 g at weaning, respectively. The overall least-squares mean pre weaning body weights were 48.39 ± 0.48, 113.65 ± 1.38, 161.50 ± 2.03, 226.15 ± 3.47, 417.89 ± 7.53g at birth, 1, 2, 3 and 4 weeks of age and the post weaning weights at 6, 8, 10, 12, 14 and 16 weeks of age were 628.75 ± 13.02, 844.11 ± 14.81, 1040.79 ± 16.42, 1225.96 ± 17.81, 1437.57 ± 20.54 and 1636.99 ± 28.87 g, respectively. Season of birth and litter size at birth showed significant (£0.01) effect on body weights while genetic group, parity of the doe and sex of the bunny had slight effects only. The low to high heritability estimates, genetic and phenotypic correlations of body weights are the indication for improvement of body weights by appropriate breeding plans.

Effect of Different genetic and non-genetic factors on Pre weaninglitter and growth performance of pigs

The study was carried out on two different genetic groups of pig viz. Duroc and Hampshire maintained at pig breeding farm of National Research Centre on Pig, Guwahati. Effect of different genetic group and non-genetic factors (year and season of farrowing and parity) were estimated by least squares analysis of variance for different litter production, weight and pre weaning growth rate. Genetic group and parity revealed highly significant (P less than 0.01) effect on all the traits under study. However, effect of year and season of birth was non significant in most of the cases. The pre weaning mortality of Hampshire pigs was found to be less than Duroc. The performance of litter production and weight traits of Hampshire pigs were found to be better than Duroc pigs in the farm.

Modelos de regressão aleatória para características de crescimento de bovinos da raça Nelore do estado de Mato Groso

Foram utilizados 138.976 registros de informações de pesos corporais variando de 60 a 610 dias de idade, provenientes de 27.327 animais da raça Nelore, oriundos de rebanhos do estado do Mato Grosso, com o objetivo de descrever a variabilidade genética e estimar parâmetros genéticos para o peso corporal em diferentes idades, utilizando-se modelos de regressão aleatória. O modelo empregado incluiu efeitos fixos de grupo de contemporâneos e idade da vaca ao parto como covariáveis, além de efeitos aleatórios genético aditivo direto, genético materno, ambiente permanente de animal, ambiente permanente materno e efeito de ambiente temporário. O modelo de regressão aleatória mais adequado foi o que empregou função de covariância com polinômios de quarta ordem para descrição da variabilidade de todos os efeitos e duas classes de variância residual. As estimativas de variância genética aditiva direta e de ambiente permanente de animal aumentaram com a idade dos animais. As variâncias genética materna e de ambiente permanente materno exibiram comportamento semelhante, com maiores valores na fase de aleitamento. Os coeficientes de herdabilidade estimados variam de 0,25 a 0,43, com maiores valores nas idades mais avançadas na trajetória de crescimento dos animais. Esses resultados indicaram presença de variabilidade genética suficiente para obtenção de ganho genético expressivo por meio da seleção, principalmente após desmama. Os resultados encontrados para a correlação genética aditiva direta exibiram baixas correlações entre pesos nas idades iniciais e finais, porém pesos altamente correlacionados entre idades mais próximas. As correlações genéticas estimadas entre os pesos da desmama com os pesos até 610 dias de idade foram altas e positivas e indicam que os genes responsáveis por maiores pesos nesse período, em sua maioria, são os mesmos.

Exposure to Folate Receptor Alpha Antibodies during Gestation and Weaning Leads to Severe Behavioral Deficits in Rats: A Pilot Study.

The central nervous system continues to develop during gestation and after birth, and folate is an essential nutrient in this process. Folate deficiency and folate receptor alpha autoantibodies (FRα-AuAb) have been associated with pregnancy-related complications and neurodevelopmental disorders. In this pilot study, we investigated the effect of exposure to FRα antibodies (Ab) during gestation (GST), the pre-weaning (PRW), and the post weaning (POW) periods on learning and behavior in adulthood in a rat model. In the open field test and novel object recognition task, which examine locomotor activity and anxiety-like behavior, deficits in rats exposed to Ab during gestation and pre-weaning (GST+PRW) included more time spent in the periphery or corner areas, less time in the central area, frequent self-grooming akin to stereotypy, and longer time to explore a novel object compared to a control group; these are all indicative of increased levels of anxiety. In the place avoidance tasks that assess learning and spatial memory formation, only 30% of GST+PRW rats were able to learn the passive place avoidance task. None of these rats learned the active place avoidance task indicating severe learning deficits and cognitive impairment. Similar but less severe deficits were observed in rats exposed to Ab during GST alone or only during the PRW period, suggesting the extreme sensitivity of the fetal as well as the neonatal rat brain to the deleterious effects of exposure to Ab during this period. Behavioral deficits were not seen in rats exposed to antibody post weaning. These observations have implications in the pathology of FRα-AuAb associated with neural tube defect pregnancy, preterm birth and neurodevelopmental disorders including autism.

Effect of broiler litter supplementation on reproductive performance of West African Dwarf sheep

Four low cost feed samples were formulated using 0, 25, 50 and 75% levels of broiler litter processed into feed along with other feed ingredients. Sixteen (16) primiparous West African Dwarf (WAD) ewes aged between twelve and eighteen months old were dewormed using Ivermectin and dipped against ticks and fleas using diazintol. Oestrus was artificially synchronized in all the ewes using Iml of Prostaglandin - 2Fα administered intramuscularly, the animals were mated with rams of known fertility and lineage bred. Ewes were evaluated in a pregnancy trial while the lambs born were evaluated in a pre weaning growth trial. All the ewes were weighed before conception and bimonthly thereafter until parturition. The parameters studied were weight at mating, weight before and after parturition, weight changes during pregnancy, weight changes in lactation and nursing, lambs birth weights and daily weight of lambs, dam's weight at weaning and gestation length. Results obtained showed weight at mating, weight before mating, weight at parturition, gestation length, weight gain in pregnancy, weight change in lactation and nursing, lambs birth weights and daily weight gain of lambs were significantly affected (p<0.05) while dam's weight at weaning and lambs' weaning weight were not affected (p>0.05). Results of this study indicate that inclusion of broiler litter up to 50% in feed mixtures of ewes has no deleterious effect on the performance and health status of ewes during pregnancy and lactation.

Uji Biologis Konsumsi Pakan, Populasi Bakteri Rumen dan pH Pellet Complete Calf Starter pada Pedet Friesian Holstein Pra Sapih

(Biological test feed intake, population rumen bacteria and ph pellet complete calf starter friesian holstein on pre weaning calf) ABSTRACT. The study aims to assess the quality of the formula Complete Calf Starter (CCS) with 5% molasses instead of milk to the development of rumen microbial calf Holstein Friesian (HF) pre-weaning. The material used is 20 head calf FH pre weaning age of 2 weeks. Feed intake data taken from 20 respondents consisted of 16 females and 4 calf tail male calf. Data rumen bacterial populations and pH were taken from 5 head of cattle slaughtered at the age of 2 weeks (one tail), 4 weeks (2-tailed) and 6 weeks (2-tailed). The study was designed as a descriptive non-parametric. Parameters measured were rumen bacterial populations, pH and feed intake. The results showed the average consumption of dry matter (DM) and CCS calf milk FH ages 2, 4, 6 weeks respectively at 506, 517, 528 grams. Rumen bacterial populations in calves aged 2, 4, and 6 weeks of 80x106, 45x106 and 19x106 kol/m. ruminal pH in calves aged 2, 4 and 6 weeks was 5.71, 5.36 and 5.55. Biological test showed that the use of complete calf starter (CCS) in the form of pellets FH calves at the age of 2 weeks to stimulate the development of the rumen (feed intake, the population of bacteria and pH) but not in calves aged 4 and 6 weeks. This is because the number of bacterial populations declined due to impaired absorption is impaired absorption of VFA marked low rumen pH.

ESTIMASI HERITABILITAS SIFAT PERTUMBUHAN DOMBA EKOR GEMUK DI UNIT PELAKSANA TEKNIS PEMBIBITAN TERNAK-HIJAUAN MAKANAN TERNAK GARAHAN

<p>Sheep is one of popular ruminants in Indonesia, because sheep is one one of source of animal protein, and also easy and convenient in breeding. Therefor, they should be developed, preserved and increased through improvement of genetic quality by selection and mating control in the breeding program. Arrangement of a breeding program requires the values of genetic parameter namely heritability. The purpose of this study was to estimate the growth heritability value of Fat Tailed sheep in UPT PT-HMT Garahan, Jember, East Java. Data were collected from progeny, birth weight and weaning weight of Fat Tailed sheep from 2007 to 2012 in UPT-HMT Garahan, Jember. Data were corrected by sex, type of birth and weaning of age. Data were analyzed using the heritability of paternal halfsib correlations and nested method of analysis. The estimation of heritabilities using paternal halfsib correlation were 0.85±0.39; 0.89±0,41 and 0.67±0.37 for birth weight, weaning weight and pre weaning average daily gain (ADG). While, heritabilities estimated from nested method were 0.89±0,48 (h2 S); -0.11±0.33 (h2 D); 0.39±0.28 (h2 S+D); 0.71±0.50 (h2 S); 0.69±0.52 (h2 D); 0.70±0.33 (h2 S+D); 0.47±0.44 (h2 S); 0.72±0.56 (h2 D); 0.60±0.32 (h2 S+D) for birth weight, weaning weight an pre weaning ADG, respectively. All growth heritabilities of Fat Tailed sheep in high category.</p><p><br />(Keyword: Fat Tailed sheep, Growth characters, Heritability)</p>

Effects of pellet diameter during and after lactation on feed intake of piglets pre and post weaning

Effects of pellet diameter during and after lactation on feed intake of piglets pre and post weaning

BRD in preweaned calves

Surveys of cow-calf producers indicate that undifferentiated bovine respiratory disease (BRD) in preweaned beef calves is recognized on approximately 20% of operations. In the US, BRD is reported to be the leading cause of death in preweaning calves 3 weeks of age and older. As compared to feedlot BRD or dairy calf BRD, relatively little information has been published regarding the epidemiology of preweaning beef calf BRD, or risk factors for the problem. However, the available information indicates that the annual incidence of preweaning calf BRD varies significantly between herds, and between years in herds that experience the problem. Calves identified with preweaning BRD have been found to weigh less at weaning than calves not identified with preweaning BRD. While more research is needed, evidence available to date indicates that at the calf level, male calves, calves born with a twin, calves born to a heifer, and calves that experience dystocia requiring major assistance are at increased risk for preweaning BRD. At the herd level, factors that have been associated with pre weaning calf BRD include those that may 1) increase the opportunity for introduction of pathogens new to the herd; 2) increase susceptibility of calves to infection; and/or 3) increase opportunity for close contact among cows and calves within the herd. Because risk factors to date have been identified in cross-sectional surveys and thus are not necessarily causative, more research is needed to confirm the factors that cause preweaning calf BRD, and to identify practices that can mitigate the disease in herds where it is a problem.

Various factors influencing birth weight in animal production

This is a review article that looks at various factors that influence birth weight in animal production. Birth weight is an important indicator of potential growth of an animal and is affected by both genetic and non-genetic factor, and the birth size depends on their interaction. Environmental conditions such as kind and quality of feed and details of management may have an influence on birth weight in livestock production. In order to minimize the adverse effects of factors that influence birth weight, it is perhaps important to understand the implications of different mechanisms, how and why they affect birth weight. Low birth weight than optimum is the main factor that determine the pre weaning losses of young ones and large birth have been associated with difficult birth. Traditional measures to ameliorate birth associated negative effects should also focus on maternal dietary manipulation which may influence optimum birth weight. Nutritional programs designed to improve dam’s body condition during pregnancy will have a positive influence on birth weight of progeny. A good knowledge of genetic parameters is essential to develop accurate selection indices and to optimally design breeding programs and performance recording systems for maximum economic gain or profit from growth traits. Estimates of genetic parameters for birth weight is model dependent and ignoring of maternal genetic effect in the model leads to overestimation of direct heritability for birth weight. Estimates of direct and maternal heritability for birth weight in different species have been reported and vary from low to high. The review article therefore, concludes that the large variability of birth weight in livestock species suggests that many factors or conditions may be responsible for this variation. The reported low heritability estimates for birth weight may be explained by the poor nutritional levels of dams creating a large environmental variation.

EFFECT OF LACTIC ACID ADDITION IN DIET ON GROWTH PERFORMANCE OF PRE WEANING PIGLETS.

Several factors are likely to influence voluntary feed intake in pre weaning and post weaning piglets, including preweaning environment, age at weaning, creep feeding and health status etc. Various nutritional approaches for optimizing the weaning transition and minimizing enteric diseases have been tested in the past decade. Various organic acids are used to increase the feed intake in pre weanling and post weanling piglets. Organic acids normally used as an acidifier in animal feeds have been considered to be alternatives for improving nutrient digestibility and growth performance of weanling pigs (Risley et al., 1992). Hence an experiment was undertaken to study the impact of lactic acid supplementation in creeper diet on growth performance of pre weanling piglets.

Proactive Management of the Equine Athlete.

Simple SummaryThe athletic career of a horse is relatively short. Career length can be positively influenced by the trainer and the age at which the horse starts competition. There are opportunities for a team approach of health professionals and changes in management to improve functional/competition life. The ability to improve the tolerance of the tissue to exercise load via the introduction of early exercise, which reflects the horse’s evolutionary cursorial lifestyle, could provide a proactive mechanism to attenuate injury risk.Across many equestrian disciplines the median competition career of a horse is relatively short. One of the major reasons for short career length is musculoskeletal injury and a consistent variable is the trainer effect. There are significant opportunities within equestrian sport for a holistic approach to horse health to attenuate musculoskeletal injury. Proactive integration of care by health professionals could provide a mechanism to attenuate injury risk and the trainer effect. However, the limited data available on current exercise regimens for sport horses restricts interpretation of how management and exercise volume could be modified to reduce injury risk. Early exercise in the juvenile horse (i.e., pre weaning) has a positive effect on stimulating the musculoskeletal system and primes the horse for an athletic career. The early introduction to sport competition has also been identified to have a positive effect on career length. These data indicate that management systems reflecting the cursorial evolution of the horse may aid in attenuating loss from sport due to musculoskeletal injury.

KINERJA KAMBING BLIGON YANG DIPELIHARA PETERNAK DI DESA GIRI SEKAR, PANGGANG, GUNUNGKIDUL

<p>This study was conducted to evaluate performances of Bligon goats kept by farmers at Giri Sekar village, Panggang sub-district, Gunungkidul as basic information for establising the village breeding centre program. The research was conducted for three months, starting from October to December 2010, located at Purwo Manunggal farmers’ group, Jerukan, Giri Sekar village, Panggang, Gunungkidul, Yogyakarta. Twenty farmers were involved during the study to be interviewed, while their goats were measured regularly. The parameter of goat meausred in this research were pre weaning, weaning, does and buck. Interviewing the farmers was done using questionnaire. Interview, direct measurement were applied to collect all required informations. The data consisted of farmer’s background, possesion of goats and land, goats’ daily management, service per conception, litter size, post partum estrus, post partum mating, kidding intervals, and average daily gain. Qualitative data were analysed descriptively and presented as percentage, while quantitative data were analysed using Independent Sample T-test, presented as mean and its standard error. The results showed that majority of the farmers (37.9%) kept goat as main sources of income, while others were to saving (34.5%) and produce manure (27.6%). On average, the numbers of goat owned by the farmers was four heads, ranging from 1 to 7 heads. The average of service per conception (S/C), gestation period, litter size, post partum estrus, post partum mating and kidding intervals of Bligon were 1.23; 5.5 months; 1.74 head; 63.2 days; 95 days and 8.53 months, respectively. The average daily gain of male kid, young and adult Bligon goats were 0.15; 0.29<br />and 0.27 kg/head/day, while for female Bligon gotas were 0.16; 0.26 and 0.15 kg/head/day, respectively. It is concluded that performances of Bligon goats was high in terms of litter size, post partum estrus, post partum mating, gestation<br />period, kidding intervals and average daily gain.</p><p>(Keywords: Performance, Bligon goats, Gunungkidul)<br /><br /></p>

POTENCY AND DEVELOPMENT STRATEGY OF SPOTTED BUFFALO IN SANGGALANGI SUBDISTRICT, NORTH TORAJA DISTRICT, SOUTH SULAWESI

The aim of this research was to analyze the reproduction performances, potency and development strategy of Torajan's spotted buffalo. This research was done from July to September 2010 in Sanggalangi’ subdistrict, North Toraja district, South Sulawesi. Purposive sampling was applied to observe data. The primary data were taken by purposive sampling method and collected by interview of 90 farmers. Results showed that sex ratio of male-female was 3:2. The first estrus was 2.48 years old, the estrus period was 23 hours and the oestrus cycle was 19 days. The first mating was 2.87 years old with the conception period about 387 days. Furthermore, the first partus was at 3.74 years old, calving interval was 2 years. Calving rate and calf crops were relatively high. Calf crops were 77%, pre weaning mortality was 2.35%. Service per conception (S/C) was 1.85 and conception rate (CR) was 86.5%. The most livelihoods in North Toraja is farmer. Spotted Buffalo population declined 24.31 % per year. SWOT analysis showed that score for internal factor was -0.25, whereas external factor was 2.25. It was showed that the sub-district Sanggalangi is in turnaround condition, so the development strategy of Torajan’s spotted buffalo has to minimize the weakness and reached the opportunities.

Comparison of purebred and crossbred D’man ewes and their terminal-sired progeny under accelerated lambing

Reproductive performance of 3137 ewe records of 957 purebred and crossbred D’man ewes and 4094 growth and survival performance of their purebred and terminal-sired progeny produced under three lambings in two years were analyzed. D’man ewes were joined to D’man (D) or Meat-Lacaune (L) rams, whereas crossbred L×D ewes were joined to Mérinos Précoce (M) rams. Data were collected from 2003 to 2007 in a private flock. As expected, D’man ewes gave birth to 0.28 lambs and weaned 0.22 lambs more than 1/2-D’man ewes, but when weight of lamb born and weaned per ewe lambed was considered, there was a tendency towards higher lamb outputs for purebred D’man ewes mated to L sires and 1/2-D’man ewes mated to M sires. Moreover, the number of lambs born and weaned from purebred D’man ewes was independent of the breed of the service sire (D or L). Lambing interval was not significantly affected by the mating type. Weight at birth and 70 days, as well as pre weaning average daily gain were influenced by the breed group of lamb, but lamb survival prior to weaning was not. Purebred D’man lambs had the lowest and M×LD crossbred lambs had the highest growth performance. Except lamb survival that was unaffected by sex, all ewe traits were influenced by season and year of lambing, and lamb growth and survival were affected by type of birth, sex, season and year of birth. It was concluded that in a terminal sire production system, using 1/2-D’man crossbred ewes would take advantage of increased reproductive capacity in the ewe without compromising lamb performance to market weight and/or product quality.

Effect of oestrus number of nulliparous sows at first service on first litter and lifetime performance

Current industry recommendations are to mate gilts on their second or third oestrous cycle (heat) to ensure that they have reached sufficient maturity and have adequate body reserves in order to sustain reproductive performance over subsequent parities. Delaying breeding has the financial implications of increased non-productive days and extra feed costs. However, these could be offset by increased fertility and/or increased lifetime productivity. The aim of this study was to investigate the effect of heat number (oestrous cycle number) on which gilts where mated on first litter and lifetime performance. In total, 157 gilts born between 2002 and 2006 were mated on either their 1st, 2nd, 3rd, 4th or 5th observed standing oestrus. Litter and reproductive data were collected on a continual basis until all animals had completed their commercial reproductive life. Sows were culled as of normal commercial practice and reason for culling was classified into groups. There was no effect (P>0.05) of oestrus number at first service on first litter performance (numbers of piglets born alive, dead, total born, average birth weight or pre weaning mortality). There was also no effect (P>0.05) on sow performance in the first lactation (feed intake during lactation, weight change during lactation or weaning to service interval). However, over their lifetime, gilts served on their fourth and fifth oestrus had significantly fewer numbers of piglets born alive (P<0.001) and weaned (P<0.001) and gilts served on their fifth oestrus also completed fewer parities compared with gilts served on their first, second or third oestrus. Gilts served on their third oestrus had the greatest (P<0.001) number of piglets born alive and weaned over their lifetime but completed a similar number of parities to those gilts mated on their first, second and fourth oestrus. However, there was no significant effect (P>0.05) of oestrus number at first service on the total weight of piglets born alive, dead or weaned over the sow's lifetime. There was no significant effect (P>0.05) of oestrus number at first service on reason for culling but there was on the culling rates of the sows between parities (P<0.05). This research found that the oestrus number that gilts are first mated on affects their lifetime performance and would suggest that the third oestrus is the optimal oestrus to mate gilts, as this resulted in these gilts producing significantly more (P<0.05) piglets over their lifetime.

Non-invasive cerebral oximetry monitoring during cardiopulmonary bypass in congenital cardiac surgery: a starting point

Non-invasive cerebral monitoring with the INVOS cerebral oximeter is an accepted good indicator of cerebral metabolism. In recent years, it has been used in the monitoring of patients who underwent cardiac surgery. Herein, we describe the INVOS trend during cardiopulmonary bypass (CPB) in a cohort of patients operated in our institution for congenital heart disease. Between December 2009 and March 2010, 40 patients (mean age 8.4 years; range 11 days-60 years) underwent cardiac surgical procedures using CPB. Values of INVOS cerebral parameter, pH, oxygen saturation, and CO(2) level were collected pre CPB, during cooling, re-warming and weaning, and post CPB. INVOS parameters were evaluated according to CPB priming, age and preoperative oxygen saturation. Patients were divided according to CPB priming (haematic vs clear), age (≤1 vs >1 year of age) and oxygen saturation (≤92% vs >92%). During the operations, the trend demonstrated a reduction in INVOS value at the institution of CPB and a further reduction during the cooling phase in all groups.This has been correlated to the loss of pulsatile flow. However, the value recovered during re-warming, weaning and CPB discontinuation. Cyanotic patients presented a lower cerebral oximetry compared to acyanotic patients during the whole CPB period. Between age and priming groups, we noticed a statistical difference in cerebral oximetry, with a lower value in the younger patients and in the haematic priming group. This might be interrelated because all patients younger than 1 year old always received haematic CPB priming. We demonstrated that cerebral oximetry decreases with the loss of pulsatile flow regardless of the mean arterial pressure and, furthermore, is not directly related to the haematocrit value in patients with reduced pulmonary blood flow.

Desempenho de cordeiras em pastagens de azevém e de milheto sob suplementação

Avaliou-se o desempenho de cordeiras em pastagens de azevém (Lolium multiflorum Lam.) e de milheto (Pennisetum americanum L. Leeke) como alimento exclusivo ou com suplementação diária com ração comercial na proporção de 0,5; 1,0 e 1,5% do peso corporal (PC). O método de pastejo utilizado foi o de lotação contínua com taxa de lotação variável. As cordeiras em pastagem de azevém com suplementação nos níveis de 0,5 e 1,5% do PC apresentaram maior ganho médio diário. Independentemente do nível, a suplementação em pastagem de azevém promoveu o maior ganho de peso por área. Na pastagem de milheto, o ganho médio diário, o ganho de peso por área e o escore de condição corporal foram maiores nas cordeiras sob suplementação. A estrutura de pastagens de azevém e de milheto não é influenciada pela oferta de suplemento aos animais. A utilização da pastagem de azevém nos períodos pré e pós-desmama, associada à suplementação nos níveis de 0,5 a 1,5% do peso vivo em pastagem de milheto, permite que cordeiras apresentem peso e escore de condição corporal adequados para o acasalamento aos 9 meses de idade.

Relative superiority of Boer x Kacang goats at pre-weaning

productivity expected from these crosses is the effect of heterosis or hybrid vigor. Boer goat is selected to improve the productivity of local Kacang goats, because this goat has a high genetic potential and has a large body formation. The objective of this research was to evaluate relative superiority of crossbreed between Boer and local goat (Kacang) during pre weaning period. The research was conducted at Goat Research Station, Sei Putih-North Sumatra, from Januari 2007 to December 2009. During pre weaning period the kids were reared with their mothers in group pen. Research results showed that birth weight and weaning weight of crossbreds (Boerka 1 and Boerka 2) were heavier than that of Kacang goat. The relative superiority of the crossbreds were 21,89 - 43,20% for birth weight, 32,88 – 54,68% for weaning weight and 37,11 – 53,32% for pre weaning daily gain. In addition the degree of mortality at pre weaning period of crossbreeds was lower than that of Kacang goats. Key words : Kacang Goat, Boer, Boerka, Relative Superiority