Pasture Height of A Tropical Erect Grass Affecting Young Lamb Herbage Intake And Performance

Tropical erect grass pastures have high forage production potential in subtropical and tropical regions of the world. However, in this kind of pasture, the body weight gain of weaned lambs is usually below of their potential. We determined the effect of pasture height of an erect tropical grass, consequently its structure, on intake and performance of young lambs. The experiment was repeated in two years. Thirty young weaned lambs (4-5 months) were assigned, each year, to three Panicum maximum pasture heights: 1) Tall-75 cm; 2) Medium-50 cm and 3) Short-25 cm. Herbage mass, pasture height, plant morphological composition, pasture nutritional quality, lamb’s average daily gain, gain per hectare and herbage intake were measured. The experiment was installed in a completely randomized design, evaluated in two periods each year. The Short treatment presented, on average and for longer, the highest leaf:stem ratio (1.3 ± 0.23) and average daily gain (91 ± 10 g/day) in relation to the Medium and Tall treatments (68 ± 10 and 40 ± 13 g, respectively). There was a significant interaction between treatment*period for herbage intake. The Tall treatment showed a marked decrease in intake from the first to the second period. The pasture height management interferes in the speed at which the number of stems increases of a tropical erect grass, in relation to leaves. For a better performance of weaned young lambs during summer-autumn period, it is important to manage tropical erect grass pastures at lower height than is generally recommended, lower than 25 cm.

Impact of mother genetic and resource environment on her offspring’s growth features in Munjal sheep

Summary The present study evaluated maternal and additive influences that contribute to phenotypic variation in various growth traits in Munjal sheep. The targeted traits that pertained to 2278 records of 706 lambs were birth weight (BWT), weaning weight (WT3), 6-month body weight (WT6), 12-month body weight (WT12), average daily gain (ADG1: 0–3 months; ADG2: 3–6 months, ADG3: 6–12 months of age) and their corresponding Kleiber ratios designated as KR1, KR2 and KR3. The direct heritability estimates for BWT, WT3, WT6, WT12, ADG1, ADG2, ADG3, KR1, KR2 and KR3 under animal models were 0.20 ± 0.08, 0.28 ± 0.08, 0.17 ± 0.07, 0.47 ± 0.09, 0.33 ± 0.08, 0.09 ± 0.06, 0.36 ± 0.10, 0.33 ± 0.08, 0.09 ± 0.06 and 0.32 ± 0.10, respectively. The estimates of maternal genetic effects contributed significantly and were 8% and 7% for BWT and WT3 traits, respectively, which highlighted the considerable role of maternal effects on early growth traits. Genetic and phenotypic correlations ranged from moderate to high between weaning and post-weaning traits. It was concluded that early selection that considered additive as well as maternal effects at weaning age may be delivered to the desired genetic progress in Munjal sheep.

META-ANALYSIS OF PHYTOGENIC ADDITIVES FOR BROILERS

Phytogenic additives have been studied intensively in broiler chickens’ production to substitute growth-promoting antibiotics. However, the comprehensive literature on this topic makes it difficult to understand overall results because there are a noticeable number of studies with conflicting conclusions. While several research studies have shown that phytogenic additives may increment broiler chicken’s performance, others make the opposite evident. This study aimed to organize and understand information through meta-analysis considering a great number of publications and the factors that may interfere in the results of phytogenic additives, evaluating whether phytogenic additives can be used as a performance-enhancing additive for broilers, comparing with the effectiveness of growth-promoting antibiotics. The main factor that interferes in the evaluation of phytogenic additives is the microbiological challenge. Phytogenic additives improved average daily gain (ADG) (P < 0.001) and feed conversion (P < 0.001) regardless of microbiological challenge; however, they were worse compared to antibiotics under higher challenge (P < 0.020). A meta-regression of ADG in function of average daily feed intake confirmed that phytogenic additives increased the feed efficiency of broilers, but with less effectiveness than antibiotics. The blends of phytogenic additives increased the ADG in relation to the isolated use of only one phytogenic additive.

Modifying the NRC weight gain model to estimate daily gain for stockers grazing bermudagrass in the southern United States

The energy requirements, feed intake, and performance of grazing animals vary daily due to changes in weather conditions, forage nutritive values, and plant and animal maturity throughout the grazing season. Hence, realistic simulations of daily animal performance can be made only by the models that can address these changes. Given the dearth of simple, user-friendly models of this kind, especially for pastures, we developed a daily gain model for large-frame stockers grazing bermudagrass [Cynodon dactylon (L.) Pers.], a widely-used warm-season perennial grass in the southern United States. For model development, we first assembled some of the classic works in forage-beef modeling in the last 50 years into the National Research Council (NRC, 1984) weight gain model. Then, we tested it using the average daily gain (ADG) data obtained from several locations in the southern United States. The evaluation results showed that the performance of the NRC model was poor as it consistently underpredicted ADG throughout the grazing season. To improve the predictive accuracy of the NRC model to make it perform under bermudagrass grazing conditions, we made an adjustment on the model by adding the daily departures of the modeled values from the data trendline. Subsequently, we tested the revised model against an independent set of ADG data obtained from eight research locations in the region involving about 4,800 animals, using 30 years (1991-2020) of daily weather data. The values of the various measures of fit used, namely the Willmott index of 0.92, the modeling efficiency of 0.75, the R 2 of 0.76, the root mean square error of 0.13 kg d -1, and the prediction error relative to the mean observed data of 24% demonstrated that the revised model mimicked the pattern of observed ADG data satisfactorily. Unlike the original model, the revised model predicted more closely the ADG value throughout the grazing season. The revised model may be useful to accurately reflect the impacts of daily weather conditions, forage nutritive values, seasonality, and plant and animal maturity on animal performance.

The Performance and Carcass Characteristics of Black Baladi Kids Fed Diets with Graded Quantities of Sweet Lupin Grain (Lupinus angustifolius)

A study was conducted to examine how lupin grains (LUPs) feeding affected nutritional intake, digestibility, growth, and carcass characteristics in kids. A total of 24 growing black kids (initial body weight (BW) = 16.4 ± 0.49 kg) were allocated to one of three diets at random. Lupin was included in the diet at a rate of 0 (control; CON), 100 (LUP100), or 200 g/kg (LUP200) of total dry matter (DM). The trial lasted for 91 days divided into 7 and 84 days to be used for adaptation and data collection, respectively. Feed intake was evaluated daily throughout the study. At the commencement and the end of the study, each kid’s body weight was measured to determine its average daily gain (ADG). On day 70, 5 kids were chosen at random from each group to investigate nutrient in vivo digestibility and N balance. At the end of the study, all of the kids were slaughtered to examine carcass features. Nutrient intakes (neutral detergent fiber, acid detergent fiber, and ether extract) were higher (p ≤ 0.01) in LUP-containing diets than in the CON diet. The average daily gain was greater (p ≤ 0.03) in diets containing lupin grains than in the CON diet. Cost of gain ($US/kg growth) was lower (p = 0.004) in kids fed diets containing lupin than the CON diet. Dry matter and CP digestibility rates were greater (p ≤ 0.03) in lupin diets. Retained N was higher (p = 0.04) in lupin-containing diets than in the CON diet. Cold carcass weight was higher (p < 0.05) for kids consuming the LUP100 diet than the CON diet. In lupin diets, carcass cut weights were higher (p < 0.05). Results of the current study indicate that feeding black kids diets containing lupin grains at 100 or 200 g/kg DM basis is cost effective and would increase profitability.

STRESS-RESISTANT OF PUREBRED AND CROSSBRED PIGS OF DIFFERENT BRED COMBINATIONS

The authors presented the results of experimental studies on the stress-resistant of pigs. The first group is a breed created in Sapphire Ltd. This breed is a breeding group (BG) in purebred breeding and their mixtures in two- and three-breed combinations with Landrace (L) and Duroc (D) boars under conditions of industrial farm technology in Siberia. Two methods assessed stress-resistant of piglets of different breed groups. The first method is “weaning crisis”. The second method is a com-parison of cortisol levels in the blood. Three-breed weanling piglets (SGxL)xD turned out to be the most stress-sensitive. Stress-resistant piglets had an effect on their growth during the rearing period. During this period, stress-resistant animals of all breed combinations had higher average daily gain than stress-sensitive animals (P < 0.001). Stress-resistant animals of the breeding group (SG) showed an average daily growth of 547.5 g during the fattening period. Also, the stress-resistant animals of the breeding group reliably surpassed the stress-sensitive pigs by 461.4 g (P < 0.01), the two-breed pigs by 455.9 g and 404.7 g and the three-breed pigs 451.8 g and 419.2 g, respectively. There was a statistically significant advantage in the indices of the average daily gain among the purebred young-sters of the breeding group (SG) (543 g) compared to the two-breed pigs (447g) and the three-breed pigs (402g), i. e., by 17.8 % and 26 % at P < 0.001. The authors found that the EAAcr/- genotype in stress-sensitive pigs was more common than EAA-/(0.71 ± 0.07 vs 0.48 ± 0.09). Stress-resistant pigs of the breeding group (SG) with EAE edg/edf blood group genotypes were characterized by increased growth intensity and reliable superiority over stress-sensitive pigs. The authors believe that these genotypes can be accepted as preliminary candidates for genetic markers of stress resistant. Blood cortisol levels appeared to be unrelated to stress-resistant compared to the “weaning crisis” method. This relationship (blood cortisol level with stress-resistant) applies to all studied breed combinations, both individually and as a whole.

Performance, carcass traits, and relative organ weight of broiler supplemented by guanidinoacetic acid: A meta-analysis

Guanidinoacetic acid (GAA) is formed by the arginine and glycine that are catalysed by arginine:glycine amidinotransferase in the kidney. In the liver, GAA is methylated by s-adenosyl methionine and converted to creatine, then deposited into muscle as energy supply. This meta-analysis was done by integrating 20 articles from various journals. Supplementation doses ranged from 0 to 8000 ppm/kg feed. The mixed model methodology was employed with GAA level and broiler strain as fixed effects and studies as random effects. The results showed that increasing GAA level improved average daily gain day 0-21 and reduced feed conversion ratio day 0-35 (P<0.05). A higher GAA also accompanied by decreasing relative liver weight (P<0.05). GAA supplementation did not affect average daily feed intake and percentage of carcass traits (carcass, legs, breast, wings, drum, thigh) and other parameters such as abdominal fat, gizzard, heart, bursa, thymus and spleen (P>0.05). It was concluded that supplementation of GAA improved the performance of broilers.

Immune status of young pigs different methods of their breeding using means Globigen® Pig Doser and Globigen® Jump Start

The article deals with the influence of the use of means for young pigs Globigen® Pig Doser та Globigen® Jump Start, which due to the content of specific Ig Y have immunostimulatory properties. Assessing the level of nonspecific resistance of piglets, which are based on determining the content of T- and B-lymphocytes and their populations in the blood of animals 30-, 60- and 120-day-old, the trend of increasing the number of T-helpers, T-natural killers and B-lymphocytes in the experimental groups of animals of both farms. It was found that the content of T-helpers during single-phase rearing of pigs became more important under the action of Globigen® Pig Doser and ranged from 30.16−35.15 %, and during three-phase rearing – under the action of Globigen® Jump Start 34.58−35.08 %. An increase in the content of B-lymphocytes to the level of physiological norm was noted: FE PE “Glynjany Agro” (single-phase cultivation) in the first experimental group 16.75–19.45 %, in the second 17.66–21.11 %. At Ltd. “Meat Resources” (three-phase cultivation) 17.7–21.02 % and 18.91–21.01 %, respectively, in the first and second experimental groups. Regarding the indicators of the content of T-natural killers, there is a tendency to increase their number in the blood of animals of experimental groups by an average of 4.90 % for single-phase rearing and 3.09 % for three-phase rearing of pigs. Such data give grounds to claim that there is a formation of the immune response to the action of pathogens, which plays an important role in maintaining the barrier function of the intestinal mucosa, which in turn reduces mortality and increases the average daily gain of young pigs. Under the action of immunostimulants, the safety of piglets in FE PE “Glynjany Agro” (single-phase rearing) at 30 days of age increased to 81.3−93.7 %, and in Ltd. “Meat Resources” (three-phase rearing) to 80.0−86.7 %. In piglets FE PE “Glynjany Agro”, up to 120 days of age, the average daily gain was 0.710 and 0.691 kg using Globigen® Pig Doser and Globigen® Jump Start, and in piglets from Ltd. “Meat Resources” these figures were 0.595 and 0.628 kg.