Supplementation of Molasses-Based Liquid Feed for Cattle Fed on Limpograss Hay.

Two experiments were performed to evaluate the effects of (1) different levels of liquid supplementation (LS) based on molasses enriched with 32% (as fed; 45% on DM basis) crude protein (CP) on intake of Hemarthria altissima hay (LH), digestibility, and rumen fermentation, and (2) different levels of LS based on molasses enriched with 32% CP in the in vitro gas production in LH diets. In Exp. 1, twelve heifers and 12 adult male castrated and cannulated cattle were used. Treatments were allocated in a randomized block design, in four treatments: (CTL) access ad libitum to the LH; (SUP2) ad libitum access to LH and supplementation with 0.9 kg d−1; (SUP4) ad libitum access to LH and supplementation with 1.8 kg d−1 and; (SUP6) ad libitum access to LH with 2.7 kg d−1. In Exp. 2, treatments were carried out in a randomized block design with four different proportions of LH diet: (CTL) 100 LH, (SUP2) 85 LH and 15 LS, (SUP4) 70 LH and 30 LS, (SUP6) 55 LH and 45% LS. In Exp. 1, liquid molasses-based supplementation did not affect LH intake (p > 0.05). Molasses intake improved as the supply increased, not reducing the intake of LH. In Exp. 2, the addition of LS to the LH caused a change in the VFA profile, with an increase in propionate production in vitro.

A meta-analytical evaluation of the effects of high-salt water intake on beef cattle.

Adequate drinking water is essential to maintain acceptable production levels in beef cattle operations. In the context of global climate change, the water scarcity forecasted for the future is a growing concern and it would determine an increase in the use of poorer quality water by the agricultural sector in many parts of the world. However, consumption of high-salt water by cattle has consequences often overlooked. A meta-analysis was carried out to assess the impact of utilizing high-salt water on dry matter (DMI) and water intake (WI), and performance in beef cattle. The dataset was collected from 25 studies, which were conducted between 1960 and 2020. Within the dataset, the water quality was divided into three categories according to the ratio of sulfates (SO4) or sodium chloride (NaCl) to total dissolved solids (TDS): 1) TDS = all studies included (average SO4:TDS = 0.4); 2) NaCl = considered studies in which water salinity was dominated by NaCl (average SO4:TDS = 0.1); and 3) SO4 = considered studies in which water salinity was dominated by SO4 (average SO4:TDS = 0.8). Results showed that DMI and WI were negatively affected by high-salt water consumption, although the magnitude of the effect is dependent on the type of salt dissolved in the water. There was a quadratic effect (P < 0.01) for the WI vs. TDS, WI vs. NaCl, DMI vs. TDS, and DMI vs. NaCl, and a linear effect (P < 0.01) for WI vs. SO4 and WI vs. SO4. Average daily gain (ADG) and feed efficiency (FE) were quadratically (P < 0.01) affected by high-salt water, respectively. This study revealed significant negative effects of high-salt water drinking on beef cattle WI, DMI, and performance. However, the negative effects are exacerbated when cattle drink high-sulfate water when compared with high-chloride water. To the best of our knowledge, this is the first approach to evaluate animal response to high-salt water consumption and could be included in the development of future beef cattle models to account for the impact of water quality on intake and performance. In addition, this meta-analysis highlights the need for research on management strategies to mitigate the negative effects of high-salt water in cattle.

Nutritive Value, In Vitro Fermentation, and Methane Production of Cactus Cladodes, Sugarcane Bagasse, and Urea.

This study evaluated the effect of different roughages fed to sheep on nutrient and water intake, ingestive behavior, nitrogen balance, microbial protein synthesis, fermentation parameters, and methane production using an in vitro gas production system. The treatments consisted of five diets: cactus cladodes Nopalea (NUB) and Opuntia (OUB), both with the addition of sugarcane bagasse (SB) and urea/ammonium sulfate (urea/as); Tifton hay (TH); corn silage (CS); and sorghum silage (SS), also with added urea/as. The NUB provided greater (p ≤ 0.03) intakes of dry matter (1024 g/d), digestible organic matter (670 g/d), and crude protein (161 g/d) than those on the SS. The NUB provided greater (p < 0.01) dietary water intake (3023 g/d) than TH. The time spent on rumination was shorter (p < 0.01), and the idle time was longer in animals fed NUB and OUB than TH and CS. Microbial protein synthesis was not affected (p = 0.27). The final pH (6.4) of the incubation fluid and the concentration of NH3-N (39.05 mg/dL) were greater for NUB and OUB. Ruminal parameters and methane production were little or not affected by tested forages. We recommend using cactus cladodes in combination with sugarcane bagasse and urea/as in sheep diets.

Prevalence of bovine subclinical mastitis, its etiology and diagnosis of antibiotic resistance of dairy farms in four municipalities of a tropical region of Mexico.

A region-wide survey was conducted in the tropical area of Tierra Caliente, State of Guerrero, Mexico to estimate the prevalence of subclinical bovine mastitis (SCM), distribution of mastitis pathogens, and in vitro antimicrobial susceptibility of different mastitis pathogens in dairy farms. In total, 1036 quarter milk samples were obtained from 259 cows at 87 different dairy farms. Collected quarter milk samples were submitted for California Mastitis Test (CMT), bacteriological examination, and testing for antimicrobial susceptibility. Overall prevalence of SCM in the studied area was 20.5 %. Prevalence in the different regions was as follows: 28 % in Arcelia municipality, 21 % in Tlalchapa municipality, 19.4 % in Pungarabato municipality, and 14.3 % in Finch Cutzamala municipality. Of all positive isolates, 97.5 % were Gram-negative bacteria. Moreover, of all positive isolates, 37.5 % were Proteus vulgaris, 25 % Salmonella spp., 12.5 % Enterobacter aerogenes, and 10 % Escherichia coli. Klebsiella pneumonia and E. coli were sensitive for netilmicin antimicrobial. However, E. coli was sensitive for pefloxacin and gentamicin with a sensitivity for pefloxacin for E. aerogenes, while Staphylococci were sensitive for gentamicin and dicloxacillin. It could be concluded that practices such as the implementation of mastitis control programs, improved milking hygiene together with an intramammary treatment with netilmicin, pefloxacin, and gentamicin antimicrobials should be considered for mastitis prevention in the study area of Tierra Caliente, in the tropical area of Guerrero, Mexico.

Diet inclusion of devil fish (Plecostomus spp.) silage and its impacts on ruminal fermentation and growth performance of growing lambs in hot regions of Mexico.

The aim of this study was to evaluate the inclusion of devil fish (Plecostomus spp.-DF) silage in Criollo × Blackbelly lamb diets in hot region of Guerrero state of Mexico. Rumen fermentation including pH, volatile fatty acids (VFA) and ammonia-N (NH3-N) and productive variables including feed intake (FI), average daily gain (ADG), and feed conversion were determined. Twenty lambs with 18 ± 1.2 kg body weight in a completely randomized design were fed a total mixed ration (TMR) of concentrate (based on soybean meal, whole oat hay, ground corn cob, vitamins-minerals supplement) with DF silage at 0 % (DF0), 9 % (DF9), 18 % (DF18), and 27 % (DF27) of the TMR for 75 days. The ruminal pH showed no difference (P > 0.05) between treatments: ranging between 6.21 and 6.36. Propionic acid molar proportions showed an irregular pattern between experimental groups, which only differed (P < 0.05) between DF9 and DF27, without differences between the other treatments. A greater molar proportion of butyric acid was noted (P < 0.05) in DF27 when compared to the other treatments. The ruminal concentration of NH3-N showed some insignificant differences (P > 0.05) among treatments. The daily FI was increased (P < 0.01) in DF27 (1.131 g) when compared with DF0, while DF9 and DF18 showed intermediate consumption with no differences (P > 0.05) among them. The ADG showed only difference (cubic effect, P = 0.02) between DF9 and DF18. The highest feed conversion was observed (cubic effect, P < 0.01) with DF18, with a value of 4.7 kg of feed to gain 1 kg of body weight. It could be concluded that the inclusion of up to 18 % of DF silage in the TMR of growing lamb diets, in hot regions of Mexico, may improve productive performance and ruminal fermentation kinetics, without any negative effects.