Fatores genéticos e de meio no intervalo de partos de caprinos leiteiros

The kidding intervals (IDP) of dairy goats raised in Southeastern Brazil were studied to quantify the influence of environmental factors and to estimate genetic parameters by means of least squares (MMQ) and restricted maximum likelihood (REML). The data analyzed were obtained from five farms and three breeds (Alpine, Saanen, and Toggenburg). The overall mean and standard error of IDP, as estimated by MMQ, were 339 +/- 12.70 days. The interaction of year x season of parturition influenced IDP. In two of the years studied, goats kidding at the end of the kidding season showed a shorter IDP when compared to those that were kidding after the end of the season. A quadratic trend of IDP over years was observed across the three kidding periods. For the three seasons. IDP increased from 1986 until mid-1989 and decreased thereafter. The heritability and repeatability of IDP, as estimated by MMQ and REML, were: 0.046 +/- 0.071 and 0.103 +/- 0.043, and 0.00026 and 0.08411, respectively. These estimates indicate that little genetic gain can be expected from selection for this trait.

SYNAPTONEMAL COMPLEX-ANALYSIS IN GOATS CARRYING THE 5/15 ROBERTSONIAN TRANSLOCATION

Synaptonemal complexes were analysed by electron microscopy in 2 bucks heterozygous for the 5/15 Robertsonian translocation. The cis configuration (free homologous 5 and 15 chromosomes on the same side of the 5/15 translocated chromosome) was found in all 50 cells examined. This feature is considered a prerequisite for the development of balanced gametes. No association between the sex bivalent and trivalent was observed.

Thermoregulatory responses of Alpine goats during thermal stress

Eight non-lactating Alpine goats, averaging 57kg, were paired according to weight and assigned randomly to 2 groups of 4 animals, control (CG) and treatment (TG) with feed and water ad libitum. An adjustment period of 7 days with all animals at thermoneutral conditions was followed by a 28-day period when TG was exposed to air temperatures averaging 35.0 degrees C, from 0800 to 1700h, including simulated solar radiation, and thermoneutral conditions from 2700 to 0800h. CG remained under thermoneutral conditions. Respiratory frequency was greater, tidal volume lower, and respiratory minute volume greater for TG than CG (176 vs 30 breaths/min, P<.001, 105 vs 293ml, P<.01; 18.4 vs 9.21, P<.05). Respiratory evaporation and sweating rate as well as rectal and skin temperatures were greater for TG than CG (14.59 vs 6.32 kcal h(-1), P<.01; 43.97 vs.00 g m(-2) h(-1), P<.001; 40.0 vs 38.9 degrees C, P<.001; 39.3 vs 35.8 degrees C, P<.01). There was no difference between groups for hematocrit and feed intake, but water consumption was greater for stressed goats than control ones (28.3 vs 29.7%; 1.44 vs 1.49 kg/day; 3.07 vs 1.26 I/day, P<.05), Final body weights of both groups were similar to initial ones. It was concluded that non-lactating goats tolerated well a 35 degrees C day temperature which is 5 degrees C above the upper critical temperature, with a black-globe temperature of 39.1 degrees C and a Botsball temperature of 28.3 degrees C, though a certain degree of hyperthermia may occur, as long as thermoneutral conditions have prevailed during the night.

Water balance in goats under feed restriction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Energy and protein requirements for maintenance and growth of Boer crossbred kids

Meat production by goats has become an important livestock enterprise in several parts of the world. Nonetheless, energy and protein requirements of meat goats have not been defined thoroughly. The objective of this study was to determine the energy and protein requirements for maintenance and growth of 34 3/4 Boer x 1/4 Saanen crossbred, intact male kids (20.5 +/- 0.24 kg of initial BW). The baseline group was 7 randomly selected kids, averaging 21.2 +/- 0.36 kg of BW. An intermediate group consisted of 6 randomly selected kids, fed for ad libitum intake, that were slaughtered when they reached an average BW of 28.2 +/- 0.39 kg. The remaining kids (n = 21) were allocated randomly on d 0 to 3 levels of DMI (treatments were ad libitum or restricted to 70 or 40% of the ad libitum intake) within 7 slaughter groups. A slaughter group contained 1 kid from each treatment, and kids were slaughtered when the ad libitum treatment kid reached 35 kg of BW. Individual body components (head plus feet, hide, internal organs plus blood, and carcass) were weighed, ground, mixed, and subsampled for chemical analyses. Initial body composition was determined using equations developed from the composition of the baseline kids. The calculated daily maintenance requirement for NE was 77.3 +/- 1.05 kcal/kg(0.75) of empty BW (EBW) or 67.4 +/- 1.04 kcal/kg(0.75) of shrunk BW. The daily ME requirement for maintenance (118.1 kcal/g(0.75) of EBW or 103.0 kcal/kg(0.75) of shrunk BW) was calculated by iteration, assuming that the heat produced was equal to the ME intake at maintenance. The partial efficiency of use of ME for NE below maintenance was 0.65. A value of 2.44 +/- 0.4 g of net protein/kg(0.75) of EBW for daily maintenance was determined. Net energy requirements for growth ranged from 2.55 to 3.0 Mcal/kg of EBW gain at 20 and 35 kg of BW, and net protein requirements for growth ranged from 178.8 to 185.2 g/kg of EBW gain. These results suggest that NE and net protein requirements for growing meat goats exceed the requirements previously published for dairy goats. Moreover, results from this study suggest that the N requirement for maintenance for growing goats is greater than the established recommendations.

Mineral requirements for growth of Moxoto goats grazing in the semi-arid region of Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Assessment of luteal function in goats by ultrasonographic image attribute analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Botulism by Clostridium botulinum type C in goats associated with osteophagia

An outbreak of botulism was detected in goats in the semiarid region of Brazil. In a flock of 460 goats, 38 does were affected and 37 died. Kids and younger goats were not affected. The main clinical signs were flaccid tetraparesis leading to tetraplegia that was often accompanied by twisted neck, tongue paralysis, and muscle tremors. At the time of the visit, 4 out of 11 affected goats were recumbent. Ambulatory goats had uncoordinated and swaying gaits with hypometria and weakness, mainly of the hind limbs. Two recumbent and four ambulatory goats showed twisted neck. Two recumbent goats were euthanized and necropsied. Non-significant gross and histologic lesions were observed. Samples of the liver, gut and rumen content were collected from the two goats and examined for botulinum toxins using the mouse serum neutralization test. The three samples from one goat were positive for type C toxin. Marked osteophagia was observed when the goats had access to bones in the pasture, and the farmer mentioned that osteophagia was common among goats of the flock. A sample of the plant Hybantus ipecaconha, the most abundant forage available for the goats, contained 2800 mg/kg of Ca and 450 mg/kg of P. One soil sample contained 58.12 mg/kg of Ca and 2.02 mg/kg of P. It was concluded that in this outbreak, botulism was associated with osteophagia probably due to phosphorus deficiency. (C) 2012 Elsevier B.V. All rights reserved.

Daily sperm production and testicular morphometry in goats according to external scrotal conformation

The present study aimed to compare testicular histology and the testicular cell population as well as spermatogenic efficiency in goats with different scrotal conformations. Eighteen goats were divided into 3 groups: Group I - goats without bipartition of the scrotum, Group II - animals with bipartition of the scrotum up to 50% of the testicular length, Group III - goats with scrotal bipartition more than 50% of the testicular length. In goats in Groups I, II and III, the values for the volume density of seminiferous epithelium were 68.9 +/- 0.6%, 71.5 +/- 2.8% and 73.4 +/- 4.7% (P < 0.05), the height of the seminiferous epithelium were 60.2 +/- 4.9 mu m, 61.0 +/- 5.0 mu m and 73.1 +/- 6.6 mu m (P < 0.05), total length of seminiferous tubules found for Groups I, II and III were 2091.9 +/- 27 m, 2172.5 +/- 24.1 m, and 2340.1 14 m (P < 0.05), number of Sertoli and Leydig cells were 1.8 +/- 0.4 x 10(9) and 1.4 +/- 0.1 x 10(9), 2.2 +/- 0.4 and 2.2 +/- 0.7 x 10(9), and 2.5 +/- 0.1 10(9) and 2.3 +/- 0.510(9)(P < 0.05)and daily sperm production observed were 2.1 0.3 x 109, 2.8 0.4 x 109, and 3.1 0.7 x 109 (P < 0.05). In conclusion, goats with greater scrotal bipartition have a greater capacity to produce reproductive cells that is reflected in a greater reproductive potential. (C) 2011 Elsevier B.V. All rights reserved.