Growth performance, carcass, and meat quality traits of Tropical Milking criollo bulls fed with two energy-level diets.

The aim of this study was to determine the effect of two energy-level diets on the beef performance of Tropical Milking criollo bulls grouped by weight and age in three periods: initial, middle, and final. Evidence on intensive beef production from Tropical Milking criollo cattle breeds are unknown, and productive alternatives for dairy producers in the hot tropics are needed. Bulls were fed in each period with low (LE, 2.2 Mcal ME/kg DM) and high (HE, 2.9 Mcal ME/kg DM) energy diets and content phase feeding protein of 14.5, 12.0, and 10.3%, respectively. For each period, ten bulls were randomly assigned to diets. In all periods, growth performance for final body weight, average daily gain, feed intake, and feed conversion were all superior in HE (p ≤ 0.05). For the final period, slaughter body, hot and cold carcass weights, and dressing were also superior in HE (p ≤ 0.05); for meat quality traits, differences were observed in muscles Longissimus dorsi, Semimembranosus, Infraspinatus, and Serratus ventralis for pH and tenderness (p ≤ 0.05), although not for diets. For color L*, a*, and b* system, neither diet nor muscle had effect on L* (p > 0.05); however, the diet-muscle interaction was significant for a* (p ≤ 0.05), and only muscle effect was detected for b* (p ≤ 0.05). Tropical Milking bulls responded positively to a high-energy diet, despite not being a beef breed.

Intensive feeding alters the rumen microbiota and its fermentation parameters in natural grazing yaks.

Introduction: Amidst the challenging environmental conditions characterized by low oxygen levels and cold temperatures on the plateau, alterations in nutrient supply emerge as pivotal factors influencing the survival and reproduction of yaks. Intensive feeding stands out as a substantial mechanism for nutrient provision, initiating discernible changes in the host's rumen flora. Within the extreme natural conditions prevailing in the plateau area of northwest Yunnan, China, there exists a con-strained comprehension of the variations in rumen microflora, fermentation parameters, and growth responses exhibited by yaks subjected to intensive feeding. Methods: This study employs 16S rRNA and ITS sequencing methods to scrutinize the rumen flora of yaks engaged in both natural grazing (G) and intensive feeding (F) on the plateau. Results: The outcomes unveil that, during the severe winter season, yaks adeptly modulate the abundance and diversity of rumen flora in response to dietary modifications under intensive feeding, aiming to optimize the efficient utilization of dietary fiber and energy. Principal Coordinate Analysis (PCoA) illustrates a substantial alteration in the rumen microbial community of naturally grazing yaks when exposed to intensive feeding. The natural grazing group manifests a higher prevalence of Firmicutes and Bacteroidetes, while the intensive feeding group exhibits heightened levels of Prevotella in the rumen. The Rikenellaceae _ RC9 _ gut_ group, associated with mycobacteria, prevails more abundantly in the natural grazing setting. PICRUSt2 analysis indicates that intensive feeding induces bacterial gene overexpression linked to protein metabolism. Rumen fungi showcase heightened diversity under intensification. Intensive feeding results in an augmented abundance of non-fiber-degrading bacteria and semi-fiber-degrading bacteria, accompanied by elevated concentrations of Volatile Fatty Acids (VFA). Discussion: These findings yield novel insights into the shifts in the rumen microflora of yaks acclimated to intensive feeding in high-altitude environments, provide an important reference for the nutritional regulation of supplemental feeding of natural grazing yaks in the cold season, ultimately contributing to their enhanced growth.

The Effect of a Bacillus Probiotic and Essential Oils Compared to an Ionophore on the Rumen Microbiome Composition of Feedlot Cattle.

The rising concern of antibiotic growth promoter use in livestock has necessitated the investigation into alternative feed additives. The effect of a probiotic and essential oils to an ionophore on the rumen microbiome composition of Bonsmara bulls raised under feedlot conditions was compared. Forty-eight Bonsmara weaners were allocated to four groups: a group with basal diet (CON) and three groups supplemented with monensin (MON), probiotic (PRO), and essential oils (EO). During the 120 days feeding period, rumen content was collected from four animals per group within each phase via a stomach tube for 16S rRNA and internal transcribed spacer (ITS) sequencing as well as volatile fatty acid analysis. In the starter phase, MON had a significantly lower acetate to propionate ratio and a higher Succinivibrionaceae abundance. The abundance of Lachnospiraceae was significantly higher in EO compared to MON. In the finisher phase, PRO had a significantly higher bacterial diversity. The alpha diversity did not differ between the fungal populations of the groups. The abundance of Proteobacteria was the lowest in PRO compared to the other groups. Limited variation was observed between the rumen microbiome composition of monensin compared to the other treatment groups, indicating that these alternatives can be considered.

Simultaneous free fatty acid elevations and accelerated desaturation in plasma and oocytes in early postpartum dairy cows under intensive feeding management.

A severe negative energy balance and high circulating free fatty acids (FFA) in postpartum cows impair fertility. The lipotoxicity of FFA has been shown to decrease the quality of bovine oocytes in vitro. Therefore, excess FFA in cells is converted to triacylglycerol (TAG), a non-toxic form, to avoid lipotoxicity. We recently reported that the TAG content in oocytes was higher in postpartum lactating cows subjected to grazing management than in heifers (Theriogenology 176: 174-182, 2021). The present study investigated the compositions of the energy metabolism-related lipids, FFA and TAG, in the plasma and oocytes of cows at different lactation stages under indoor intensive feeding management in order to obtain insights into lipotoxicity in oocytes, particularly those in early postpartum cows. Blood and oocytes were collected from 20 lactating cows categorized into the following lactation groups: 20-30 days in milk (DIM) (n = 5), 40-50 DIM (n = 5), 60-80 DIM (n = 5), and 130-160 DIM (n = 5). Daily energy balance data were obtained for 3 weeks prior to oocyte collection using the ovum pick up (OPU) method. The contents and compositions of FFA and TAG in plasma and oocytes were analyzed using liquid chromatography-mass spectrometry. As expected, plasma FFA was high at 20-30 DIM, decreased by 50 DIM, and was maintained at a low level for the remainder of the experimental period. Similar changes were observed in oocyte FFA and TAG with DIM as plasma FFA. Oocyte FFA positively correlated with plasma FFA (P < 0.05), but negatively correlated with the mean energy balance 1 and 21 days before OPU (P < 0.05). Relationships were noted between the composition and content of FFA in plasma and oocytes, with the FFA 16:1/16:0 and 18:1/18:0 ratios positively correlating with the total amount of FFA (P < 0.05). Elevated oocyte FFA in cows in the early postpartum period under intensive feeding management suggested that oocytes were at a high risk of FFA lipotoxicity. Furthermore, the present results implied that the severe negative energy balance in the previous few weeks was closely related to increases in oocyte FFA, which supports the importance of long-term cow feeding management for preserving the quality of oocytes in the early postpartum period. The present results provide insights into the effects of high circulating FFA on the fertility of postpartum cows.

Gastrointestinal Conditions in Children With Severe Feeding Difficulties.

Feeding aversion in children may progress to severe feeding difficulties. While oral-motor and sensory issues are usually the leading causes, organic etiologies should be considered. This study aimed to assess the prevalence of gastrointestinal conditions in children with severe feeding difficulties. We conducted a retrospective study of 93 children requiring an intensive feeding program. The medical records, radiologic and diagnostic tests, use of gastric tube feedings, preexisting medical conditions, and medications were reviewed. Fifty-two percent (52%) had esophagitis, 26.2% gastritis, and 40.7% lactase deficiency in upper endoscopy. In those who underwent an upper endoscopy, 26% of patients that were also tested for small intestinal bacterial overgrowth were found to be positive. Allergy testing was abnormal in 56.6% of those tested, while 27.5% and 75% had abnormal gastric emptying times and pH impedance results, respectively. Constipation was present in 76.3%. Thirteen of 32 were weaned off tube feedings. We conclude that gastrointestinal conditions are common in children with feeding disorders and should be investigated prior to feeding therapy.