Effect of Suckling Management and Ewe Concentrate Level on Methane-Related Carbon Footprint of Lamb Meat in Sardinian Dairy Sheep Farming

The aim of this study was to estimate the methane-linked carbon footprint (CF) of the suckling lamb meat of Mediterranean dairy sheep. Ninety-six Sarda dairy ewes, divided into four groups of 24 animals each, were assigned to 2 × 2 factorial design. The experiment included the suckling lamb feeding system: traditional (TS), in which lambs followed their mothers on pasture during grazing time, vs. separated (SS), in which lambs remained indoors, separated from their mothers during the grazing time. Each group was divided into high (HS) and low (LS) supplemented ewes (600 g/d vs. 200 g/d of concentrate). The estimated CH4 emission of the ewes, calculated per kg of body weight (BW) gain of the lamb during the suckling period, was then converted to CO2eq with multiplying factor of 25. The TS lambs showed lower methane-linked emissions than SS ones (p < 0.05). The sex of lambs affected their methane-linked CF, with males having lower (p < 0.05) values than females. Twins displayed much lower methane-linked CF than singles (4.56 vs. 7.30 kg of CO2eq per kg of BW gained), whereas the level of supplementation did not affect greenhouse gases (GHG) emission. Interaction displayed lower and not-different GHG emissions for both indoor- and outdoor-reared twins. In conclusion, the methane-linked CF of the suckling lamb meat can be reduced by maintaining the traditional lamb rearing system and by improving flock prolificacy.

Effects of dietary forage to concentrate ratio on nutrient digestibility, ruminal fermentation and rumen bacterial composition in Angus cows

This study evaluated effects of dietary forage to concentrate ratio (F:C) on the body weight, digestibility, ruminal fermentation and rumen bacterial composition in Angus cows. Three diets with different F:C (LCD: 65:35, MCD:50:50, and HCD: 35:65) were fed to ninety Angus cows (3.2 ± 0.18 years old, 387.2 ± 22.6 kg). The average daily gain (ADG) and ammonia nitrogen concentration increased (P = 0.039 and P = 0.026, respectively), whereas the acetate to propionate ratio (P = 0.027) and the neutral detergent fiber (NDF) digestibility decreased with increasing concentrate level. The acetate concentration and ruminal pH (P = 0.033 and P = 0.029, respectively) decreased by feeding HCD diet. Serum amyloid A (SAA), C-reactive protein (CRP), haptoglobin (Hp) and lipopolysaccharide binding protein (LBP) increased under the HCD. The relative abundances of Bacteroidetes, Fibrobacterota, Prevotella and Prevotellaceae UCG-003 decreased, whereas the relative abundances of Ruminococcaceae NK4A214 group, Saccharofermentans and Spirochaetota increased with increasing dietary concentrate level. Our study provides a better understanding of rumen fermentation parameters and microbiota under a wide range of dietary F:C ratios, supporting the potential dietary manipulation of microbes, which could enhance feed digestibility associated with cow rearing.

Effect of low and high concentrate supplementation on health and welfare indicators in different breeds in small-scale mountain dairy farms

We investigated and compared the effects of low and high concentrate supplementation in terms of animal welfare, health and reproductive performance in two different dairy cow breeds on small-scale mountain farms. 64 South Tyrolean dairy farms were evaluated using an on-farm assessment for animal-based and resource-based welfare indicators, data from test day records, and a questionnaire for the farmer. Farms were divided into four groups: low input Tyrolean Grey (L-TG), low input Brown Swiss (L-BS), high input Tyrolean Grey (H-TG) and high input Brown Swiss (H-BS). Effects of intensity level, breed and their interaction were calculated and analyzed statistically. The predominant husbandry system across all groups was tie-stall. The average energy-corrected milk yield increased with increasing concentrate level, with L-TG showing the lowest and H-BS showing the highest milk yield. Age at first calving was lowest in H-BS when compared to all other systems, while numbers of lactations were higher in L-TG compared to H-BS. Feed efficiency (percentage of milk out of roughage) was significantly higher in L-TG and L-BS when compared to H-TG and H-BS. L-BS showed the poorest results for most of the welfare indicators such as lean cows, lesions and percentage of dirty animals. In conclusion, a higher concentrate level in diets does not lead automatically to lower animal welfare for dairy cows in alpine regions. Indeed, keeping high yielding breeds in extensive systems seems to be challenging. The dual-purpose breed TG showed some clear advantages in that calving interval was lower and the number of lactations greater.

The ratio of roughage to concentrate on milk secretion rate in goats fed Stylosanthes ha mata hay

An experiment was conducted to evaluate the effect of roughage to concentrate ratio (R:C) on milk secretion rate (g/h) in goats using a cross-over design in which each goat passed sequentially through all the treatments in random order. The treatments (R: C) were: A = 70 percent roughage : 30 percent concentrate; B = 50 percent roughage : 50 percent concentrate e and C = 30 percent roughage : 70 percent concentrate. In the experiment, seven goats were milked once a day, from the 2nd to 8th week of lactation, thrice per week for 2 weeks per treatment. The animals were fed at 4 percent body weight (DM basis). The feed consisted of Stylosanthes hamata hay (S. hamata hay) and a 17.2 percent CP concentrate ration. Data were analysed using the treatments as main effect with live weight and week of lactation as covariates. There was no significant treatment effects on mülk secretion rate (P>0.05). Overall milk secretion rate was 5.23gh. Week of lactation also had no significant effect (P>0.05). However, live weight of doe at time of milking had a highly significant effect (P>0.001) with milk secretion rate increasing by 0.41g/h per kilogram live weight. The R2 values for the predictive mathematical relationship for goats fed Stylosanthes hamata hay at 4 percent body weight in the dry season was R2 = 0.888. It can therefore be deduced that for a ladating doe in the 5th week of lactation at 20kg body weight fed at 4 percent with Stylosanthes hamata hay to concentrate ratio at 70 percent roughage : 30 percent concentrate would give a milk secretion rate of 6.717g/h while at 50 percent roughage : 50 percent concentrate it would give 6.662 g/h and 30 percent roughage : 70 percent concentrate level would give 7.054 g/h. Keywords:,,,

FEEDLOT PERFORMANCE AND CARCASS TRAITS OF YANKASA RAMS. I — EFFECT OF VARYING THE CONCENTRATE TO ROUGHAGE RATIO

Thirty-five Yankasa rams initially weighing 22.5kg on the average were individually fed one of five diets formulated to differ in the roughage to concentrate ratio: 70:30, 60:40, 50:50, 40:60, 30:70. The diets were isonitrogenous and isocaloric. Average daily gain (ADG) and feed efficiency show­ed a linear response to increasing levels of dietary concentrate. Feed intake on the other hand did not reveal any significant difference. Both dry matter and nitrogen digestibility tended to increase with in­creasing dietary concentrate. Dressing percentage, kidney and mesenteric fats also increased with in­creasing concentrate level. Given the overall perfor­mance and current prices of feedstuffs, rams and mutton, it would seem that 50 to 60% dietary con­centrate is optimal for fattening.

PSX-8 Effects of dietary concentrate level and limited feed access on feed intake and performance by lactating Alpine dairy goats

The objective was to determine if effects of different limited feed access treatments on performance by lactating Alpine dairy goats vary with dietary concentrate level. Primiparous (29; 55.2±0.8 kg BW) and multiparous Alpine goats (29; 70.2±1.06 kg) were used in a 24-wk study of 3 8-wk phases beginning at 7.1±0.37 d after kidding. Diets of 40 or 60% concentrate (40C and 60C, respectively) were offered free choice in Calan gate feeders, with access continuously (CON), for 8 h between morning and afternoon milkings (DAY), or for 2 h after each milking (FRH). Although there were many interactions involving phase, ADG during the entire study was greater for CON vs. FRH (P &lt; 0.05; -20, -41, and -61 g for CON, DAY, and FRH, respectively; SEM = 8.6). Intake of DM also was greater for CON than for FRH (P &lt; 0.05; 2.17, 2.03, 2.01, 2.29, 2.07, and 1.80 kg/d for 40C-CON, 40C-DAY, 40C-FRH, 60C-CON, 60C-DAY, and 60C-FRH, respectively; SEM=0.093). There were interactions (P &lt; 0.02) between concentrate level and access treatment in milk yield (2.55, 2.41, 2.61, 3.21, 2.66, and 2.27 kg/d; SEM=0.103) and protein concentration (2.65, 2.55, 2.60, 2.67, 2.70, and 2.49%; SEM = 0.042), and milk fat concentration was greatest among treatments (P &lt; 0.05) for FRH (2.79, 2.77, 3.18, 2.86, 2.89, and 3.02% for 40C-CON, 40C-DAY, 40C-FRH, 60C-CON, 60C-DAY, and 60C-FRH, respectively; SEM=0.103). As a consequence, milk energy yield was 6.14, 5.70, 6.67, 7.83, 6.58, and 5.61 MJ/d (SEM=0.251) and the ratio of milk energy to DMI was 3.01, 2.87, 3.37, 3.47, 3.28, and 3.18 MJ/kg for 40C-CON, 40C-DAY, 40C-FRH, 60C-CON, 60C-DAY, and 60C-FRH, respectively; SEM=0.123). Overall, limited feeder access treatments did not improve performance and, in fact, the shortest access treatment increased BW loss; however, efficiency of feed DM usage for milk energy yield was not adversely impacted.

PSIV-23 Variations in chewing behavior and rumino-reticular pH in dairy cows during gradual adaptation to a high-grain diet

Physical effective fiber in the diet promotes chewing, contributing to the regulation of ruminal pH through saliva production, which leads to rumen health. However, lower dietary fiber content in high-grain diets may reduce rumination time and compromise ruminal pH regulation. The objective of this experiment was to evaluate rumination behavior and rumino-reticular pH variations during an 8-day adaptation to a 65% concentrate diet. For this study nine ruminally cannulated non-lactating Holstein cows were used. Prior to the initiation of the adaptation, cows were transitioned from a forage-only grass silage diet to a 65% DM concentrate diet over eight days. Rumination was monitored using RumiWatch halters (RumiWacthSystem ITIN+HOCH). Rumino-reticular pH was measured using eCow indwelling pH systems in five of nine cows recording data every 15 minutes. Data were analysed with SAS, the statistical model included day as fixed effect and cow was considered as random effect. Adaptation days had an effect (P &lt; 0.01) on rumination time, number of rumination chews per minute, and mean daily (rumino-reticular) pH. Especially, rumination time decreased from 439 to 327±62.8 minutes per day from day 1 to 8, respectively. Concomitantly, rumination chews per minute decreased from 68.8 to 65.6±2.06, and mean daily pH decreased from 6.54 and 6.26±0.07, respectively. Nevertheless, daily dry matter intake (P = 0.23) and eating time (P = 0.37) were not affected during the adaptation period. In conclusion, adaptation to a high-grain diet and the associated decrease in physically effective fiber gradually reduced chewing activity and ruminal/reticular pH. However, compared to the forage-only diet, significant reduction in rumination time was only noted at the 65% concentrate level.

Effect of dairy cow genotype and concentrate feed level on cow performance and enteric methane emissions during grazing

The current study (40 cows in a 2 × 2 factorial arrangement) compared methane (CH4) emissions from two dairy cow genotypes (Holstein-Friesian [HF], and Swedish Red × [Jersey × Holstein-Friesian] [Crossbred]) offered two levels of concentrate supplementation (3.0 or 6.0 kg/cow per day) while grazing. Enteric CH4 emissions were measured using the SF6 technique on three occasions over a 16 week period, while intakes were estimated using performance data. Increasing concentrate level increased milk and energy corrected milk (ECM) yields, had no effect on CH4 emissions (g day-1) and CH4 emissions per kg dry matter (DM) intake, while reducing CH4/ECM yield. Crossbreds produced milk with higher milk fat and protein contents than HF cows, but ECM yield did not differ between genotypes. Daily CH4 production (g day-1), and CH4 production per kg ECM yield was unaffected by genotype. Methane yield (g kg-1 DM intake) was higher with the Crossbred cows, although DM intake was estimated in this study, and this result should be interpreted with some caution. Thus HF and Crossbred cows had similar CH4 emissions.

Effect of feeding level during the prepubertal phase on mammary gland development in female goat kids

The experiment reported in this research communication aimed to determine the effects of post-weaning feeding level after early weaning on mammary parenchyma development in Alpine goats. Thirty Alpine female goat kids were weaned early (at around 9.8 kg and 32 d of age) and fed different levels of concentrate: Control (C, 730 g DM/d, n = 10), Low (L, 365 g DM/d, n = 10) or High (H, 1090 g DM/d, n = 10) until 235 d of age with ad libitum hay and water. Half of the goat kids were slaughtered before puberty (at around 208 d of age) and half at midgestation (at around 308 d of age and 70 d of gestation) for mammary parenchyma sampling. A histological analysis, Western blot and DNA quantification were performed. Blood samples were taken before puberty and at midgestation to determine plasma levels of IGF-I and prolactin. The mammary gland weights before puberty and at midgestation were positively and significantly associated with concentrate level. However, the organization of the mammary parenchyma and protein expression and quantity of DNA in the parenchyma were similar among the three groups. Before puberty, prolactin and IGF-I concentrations were significantly increased by the feeding level. In conclusion, feeding level after early weaning did not impact mammary parenchyma structure although it modified the weight of the mammary gland. The establishment of the mammary gland was not impacted by rearing management before puberty. Hence, increasing the feeding level during the rearing period could be an interesting way to increase the body development of goats without impairing mammary development whilst having a positive impact on reproductive parameters such as litter weight.

Performance of crossbred lactating cows at grazing in response to nitrogen supplementation and different levels of concentrate feed

ABSTRACT The performance of crossbred (1/2 Holstein x Zebu) cows supplemented on Brachiaria decumbens pasture during the wet-dry transition period was evaluated. Eight cows with 497±50kg, during third and fourth lactations and after the lactation peak were distributed in two 4 x 4 Latin squares. The treatments consisted of a factorial with two types of mineral supplements (nitrogenous and mineral salt) and two levels of concentrate (0.3 and 0.6% body weight (BW)/cow/day), based on corn and soybean meal (60:40), and supplied during the morning and afternoon milking. The experiment lasted 56 days, divided into four periods of 14 days, with seven days for adaptation and seven for data collection. No interaction (P> 0.05) was observed between the supplements and the concentrate levels. The nitrogenous salt and the highest concentrate level increased (P< 0.05) the intake of crude protein, and the highest concentrate level increased (P< 0.05) the intake of non-fibrous carbohydrates and the digestibility of crude protein. No effect (P> 0.05) of supplement and concentrate level was observed on the milk constituents and feed efficiency. Grazing crossbred after the lactation peak during the wet-dry transition period achieve the productive potential with 0.3% BW of concentrate per day and mineral salt.