Tropical animal health and production最新文献

The study investigated selenium's (Se) efficiency in preserving South African Zulu rams' sperm quality and testicular parameters when they were exposed to heat stress. Indigenous Zulu rams (20) between 2 and 5 years old were allocated into four groups, namely the Se, testicular heat stress (THS), selenium plus testicular heat stress (SeTHS), and control. Each group comprised five rams; the groups were balanced according to the rams' body weight and scrotal circumference. The Se and SeTHS groups received sodium selenite orally bi-weekly for 5 months. To induce heat stress, testicular heat insulation bags were wrapped around the testes of the rams receiving the THS and SeTHS treatments for 49 days. Semen was collected from the rams weekly from the third month onward; the first two months were for Se & THS acclimatization. In addition, testicular measurements were taken bi-weekly. Analysis of variance was used to analyze the sperm quality data. Duncan's multiple range test was used to compare the groups' data for significant differences. The results showed that the Se-supplemented rams' scrotal circumference was smaller (p < 0.05) compared with the other groups. The Se, SeTHS, and control groups demonstrated similar total sperm motility; in contrast, the THS and SeTHS groups recorded low and high total sperm motility, respectively, compared with other treatment groups (p < 0.05). The semen from the rams that received THS without Se displayed a significantly higher number of immotile sperm cells (p < 0.05) and poor sperm quality, including total and progressive motility, and kinematic parameters when compared with other treatments, suggesting that Se protects sperm against THS. We concluded that selenium protected some sperm parameters (TSM, PSM, MV, VCL, VSL) of THS- treated rams while others did not improve (RV, NSM, C, STR).

The valorization of agro-industrial byproducts in domestic animal feed has the potential to reduce the cost of animal production. This trial was conducted to determine the effect of incorporating prickly pear byproducts (envelopes and cakes) as a partial substitute for corn and soybean meal in the diet of wheat quails (Coturnix coturnix) during their rearing period. Six hundred-day-old Coturnix coturnix quails of equal sex ratio (1:1), weighing on average 7 ± 0.5 g, were randomly distributed into four groups, one control group and three experimental groups, according to the rates of incorporation of prickly pear cakes and envelopes, in sequential or nonsequential mode, in the different rearing phases. Each batch (150 subjects) was subdivided into five packs of 30 animals and randomly distributed according to the rate of incorporation (0%, 10%, 20% and 30%) of prickly pear envelopes and cakes. The live weight at 45 days and average daily gain (ADG_1 - 45d) increased significantly with the introduction of byproducts in all rearing phases (SF_CEPP). The carcass yield increased significantly (p < 0.05) with the introduction of byproducts in the finishing phase (F_CEPP) and in all rearing phases (SF_CEPP). The mineral content decreased significantly (p < 0.05) in all the experimental groups. The protein content increased significantly by 2 points on average when the two prickly pear byproducts were introduced in all rearing phases. The blood biochemical profile of each experimental batch was not influenced by the incorporated prickly pear byproducts. Prickly pear envelopes and cakes in wheat quail feed improve growth performance and meat quality, particularly when they are introduced in the finishing phase and in all rearing phases.

The prediction of live weight (LW) is of critical importance to farmers in a range of applications, including breeding and monitoring animal growth. In this context, Ridge, Least Absolute Shrinkage and Selection Operator (LASSO), and Elastic Net as shrinkage methods, and Classification and Regression Trees (CART) and Random Forest (RF) as tree-based regression methods were used in this study to predict LW of Akkaraman Sheep at 6-month age using sex, birth weight (BW) and some morphological traits such as withers height (WH), chest depth (CD), body length (BL), chest width (CW), rump height (RH), and chest circumference (CC). The dataset of 100 sheep, consisting of 44 males and 56 females, was randomly divided into training and test sets with a ratio of 80% and 20%, respectively. 10-fold cross-validation method was implemented using the training set to obtain optimum regression models and avoid overfitting. A test set was used to compare the prediction performance of regression methods based on various comparison criteria. Results revealed that LW was significantly correlated with all morphological traits and BW with coefficients ranging from 0.216 to 0.757. RF outperformed the other regression models with a coefficient of determination value (R²) of 0.865, followed by Ridge (R² = 0.761), LASSO (R² = 0.755), Elastic Net (R² = 0.750), and CART (R² = 0.654). The results indicated that WH and CD contributed the most, while sex and BW contributed the least in constructing the optimum RF model. In conclusion, the use of RF is recommended for predicting the LW of Akkaraman sheep. These results can provide a data-driven approach to improve decision-making in animal breeding.

Fodder scarcity and low quality affect the productivity of dairy cattle in Kenya yet only few smallholder dairy farmers show positive deviance in fodder conservation. Information on the strategies of such positive deviant (PD) farmers is scanty. The objective of this study was to determine strategies that distinguish PDs from peers (non-PDs) in fodder conservation among smallholder dairy farmers in highlands and midlands of Kenya. A cross-sectional survey was conducted among farms producing and conserving fodder in Tharaka Nithi County. Multistage sampling procedures was used; purposive sampling of the Sub-counties and locations, random selection of villages and proportional selection of 246 farms through snowball chain referral. Data were collected on demographic, socio-economic, farm characteristics and fodder conservation. Farms were categorized as PDs (n = 24) or non-PDs (n = 97). The PDs conserved fodder adequate to last dry season (about 3 months) and had milk yield 15 kg/cow/day and above, while non-PDs do not qualify for both criteria. Chi-square and T-test were used to analyze categorical and continuous variables respectively. Logit regression was used to examine independent variables that influence probability of PDs. Farmers with high school and tertiary education who accessed extension services were PDs while non-PDs had non-formal and primary education and access extension less. Farms conserving hay and silage dominated PDs. Land in hectare (ha) and herd sizes in Tropical Livestock Unit (TLU) distinguished PDs (1.7 ha and 9.0 TLU) from non-PDs (0.7 ha and 3.3 TLU). The strategies that distinguished PDs from non-PDs were allocating land to fodder production, high milk yield kg/cow/day, large herd size and access to extension services. Increasing access to extension and resources (land) raised chances of PDs in fodder conservation. Knowledge of PDs strategies is important for fodder conservation, improve productivity and inform direction of future research.

This study utilized a dataset comprising 3023 lactation records for Friesian cows, 596 records for Native cows (Baladi), and 1189 records for Crossbred cows spanning from 1994 to 2015. The objective was to estimate and assess genetic and phenotypic parameters and breeding values for 305-day milk yield (305-DMY), lactation period (LP), calving interval (CI), and days open (DO) within the Egyptian dairy context. The motivation for this research stemmed from the need to understand the genetic potential of different cattle genotypes in Egypt and identify opportunities for enhancing dairy production. Data were analyzed using the linear mixed model least squares and maximum likelihood (LSMLMW) and multiple-trait derivative-free restricted maximum likelihood (MTDFREML) programs. The analytical model included fixed effects such as season and year of calving, parity, and genotype groups, while random effects included animal and error. Unadjusted means for 305-DMY, LP, CI, and DO were calculated for each genotype group. Genotype groups significantly impacted all studied traits. Heritability estimates varied across genotype groups, with higher estimates observed in Crossbred (0.32, 0.26, 0.25, 0.23) and Native cows (0.26, 0.28, 0.28) compared to Friesian cows (0.24, 0.22, 0.16, 0.17) for productive and reproductive traits, respectively. Genetic correlations among traits ranged from 0.10 to 0.86 for the three genotype groups, while corresponding phenotypic correlations were generally small to moderate and positive. Regarding breeding values, the accuracy estimates suggested that both sires and cows could contribute to genetic improvement. This indicates the potential for enhancing dairy production through selective breeding strategies.

The objective of this study was to evaluate the intake and digestibility of nutrients, production and composition of milk, and water intake of lactating dairy cows fed standard diets in which ground corn (C) was replaced by up to 100% in the diet by cactus pear (CP). Eight Girolando cows (½ Gyr x ½ Holstein), 3rd calf multiparous, with 60 to 80 days of lactation and an average weight of 450.0 ± 30.0 kg, were randomly distributed in a double Latin square (4 × 4). Four experimental diets were evaluated: (100% C + 0% CP), (66.6% C + 33.3% CP), (33.3% C + 66.6% CP), and (0% C + 100% CP). There was a difference (P < 0.05) in the intake of CP and EE (kg.day^- 1), with a quadratic effect and a linear reduction, respectively, with substitution. The maximum CP intake of 3.05 kg.day^- 1 was found at 46.07% and EE intake fell by 3.81 g for each percentage unit of cactus pear added to the diet. There was a quadratic difference (P < 0.05) for DM intake in %BW and g.kg BW^0,75, with maximum values of 3.97%BW and 186.8 g.kg BW^0,75 with the substitution of 54.83 and 53.17%, respectively. There was a quadratic effect (P < 0.05) for the intake of NDF in %BW, with the maximum intake of 1.3% at the 74.69% substitution level. There was a linear reduction (P < 0.05) in the digestibility of DM, NDF, and TDN, and for the other nutrients there was no substitution effect (P > 0.05). There was no difference (P > 0.05) in milk production and composition. There was a linear reduction (P < 0.05) in water intake. Cactus pear can be used in a promising way to replace ground corn up to 100% in the diet of lactating dairy cows.

Sheep were among the first animals domesticated by humans, and to this day, small ruminants are primarily raised for their meat, milk, and wool. This study evaluated the goodness of fit for growth curve models using observed age and weight data from crossbred lambs of various breeds based on the mean values between paired breeds. We employed a hybrid metaheuristic algorithm, combining a simulated annealing (SA) algorithm and a genetic algorithm (GA) called SAGAC, to determine the optimal parameter values for growth models, ensuring the best alignment between simulated and observed curves. The goodness of fit and model accuracy was assessed using the coefficient of determination (R²), Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Mean Absolute Percentage Error (MAPE). Errors were measured by comparing the criteria differences between simulated and observed data. Thirty crossbreed combinations were simulated, considering the average weight. Analysis of the observed and simulated growth curves indicated that specific crossbreeding scenarios produced promising results. This simulation approach is believed to assist geneticists in predicting potential crossbreeding outcomes, thereby saving time and financial resources in field research.

Nutritional modifications to improve meat quality is targeted by farmers. Bird eye pepper (BEP) contains bio-compounds of physiological significance. The potency of BEP of varying inclusion level and sieve size on meat quality [fatty acid (FA), lipid profile and oxidative stability] of broiler chickens was investigated. A total of 246 birds fed diet-containing BEP [inclusion level (0, 0.15 and 0.3%), sieve size (0.05 and 0.1 mm)] were randomized to six treatments replicated 4 times in a 2 by 3 factorial layout. After feeding (31 days), forty-eight birds (two per replicate) were slaughtered and breast muscles harvested. Meat lipid profile and 2-thiobarbituric acid reactive substance (TBARs) were determined on day (d) 0, while TBARs was further assessed on d 3 and 5, but FA on d 10 of refrigeration storage. BEP diet (0.15%) increased (p < 0.05) total monounsaturated FA (MUFA), unsaturated FA (UFA) and n-3 FA, while 0.05 mm BEP lowered (p < 0.05) meat index of thrombogenicity (TI) but increased meat hypocholesteromic: hypercholesteromic (HH) value. Dietary 0.15% (0.05 mm) BEP yielded low (p < 0.05) SFA but high MUFA: SFA, UFA: SFA and NVI, while 0.15% (0.1 mm) BEP diet resulted in high total MUFA and higher (p < 0.05) UFA, n-3 and n-3: n-6 FA. Control, 0.15% and 0.05 mm BEP diets reduced (p < 0.05) meat cholesterol value. This study has shown that 0.15% (0.05 mm) BEP diet had no deleterious effect on the growth of broiler chickens but improved the NVI, IA, TI, HH, TBARs and cholesterol of the meat - a significance to health-conscious consumers.

This study aimed to investigate the effect of diet supplementation with a symbiotic (SY), bee pollen (BP), honey bee (HB), date palm pollen (DPP) and their mixture (MIX) on female rabbit productive and reproductive performances under desert hot climates. Seventy-two Californian does of 5 months age and average body weight of 3250 ± 78.2 g were randomly allotted into six groups, each of 12 does. All does orally receive 3 ml distilled water for 10 days before mating and 28 days during pregnancy. Treatments were repeated for four consecutive parities. The first group served as control (C) given distilled water only, however the second, third, fourth and fifth groups were supplemented with 3 ml distilled water containing 0.2 ml SY, 200 mg DPP, 200 mg BP, 0.2 ml HB/doe per day, respectively. While, the sixth group does were given all previous ingredients (MIX). Sexual receptivity rate, fertility rate, kindling rate, and newborn traits were recorded. Also, maternal feed intake, feed conversion ratio, and digestibility coefficients of nutrients were recorded. Does in all groups were artificially inseminated with 0.5 ml of fresh heterospermic semen of 15 fertile bucks extended in Tris at 806-1006 sperm/ml. Treatment increased maternal body weight and daily gain with highest values (P < 0.05) in BP, SY, and MIX does. All treatments enhanced feed intake and feed conversion ratio (FCR) compared with control. Number services per conception decreased (P < 0.01), while litter size and weight and survival at birth and weaning increased (P < 0.01) in treated than control does. Treated does produced more milk than control. Digestibility coefficients of all nutrients were improved (P < 0.01) in treated does. In conclusion, supporting rabbit does pre- and during pregnancy with diets supplemented with a mixture of honey bee, date palm pollen, bee pollen, and synbiotic improves the productive and reproductive performances of rabbit does and their offspring.