Variation of TMR particle size and physical characteristics in commercial Iranian Holstein dairies and effects on eating behaviour, chewing activity, and milk production

Feeding Byproduct-Based Concentrates Instead of Human-Edible Feed Ingredients Increases Net Food Production and Improves Performance of High-Producing Holstein Cows

Simple Summary

The effect of replacing human-edible feed ingredients with byproducts on the performance and net food production of high-producing Holstein dairy cows was investigated. Feeding byproduct-based concentrate instead of human-edible feed ingredients increased net food production and improved the performance of high-producing Holstein cows.

Abstract

The effect of feeding greater amounts of byproducts (BP) as a replacement for human-edible (HE) feed ingredients on nutrient intake, chewing activity, rumen fermentation, production performance, human-edible feed conversion efficiency (HeFCE) and net food production (NFP) of high-producing Holstein cows was evaluated. Twelve multiparous Holstein cows (BW = 673 ± 44, DIM = 112 ± 8 d; 48 ± 2.25 kg/d of milk; mean ± SE) were used in a replicated 3 × 3 Latin square design with 28-d periods. Each period consisted of 21 d of adaptation followed by 7 d of data collection. Treatments diets were (DM basis): (1) concentrate containing 26% byproducts (BP26; control); (2) concentrate containing 60% byproducts (BP60); and (3) concentrate containing 95% byproducts (BP95). Alfalfa hay (20% dietary DM) and corn silage (20% dietary DM) were included in all diets. Dietary concentrations of neutral detergent fiber (NDF), non-fiber carbohydrates (NFC), starch and ether extract (EE) were 32.1, 41.0, 26.14 and 3.4% (BP 26); 35.3, 36.0, 22.05 and 4.7% (BP60); and 38.2, 32.0, 17.96 and 6.1% (BP95), respectively (DM basis). Dry matter (22.07 kg/d) and NEL (35.16 Mcal/d) intakes did not differ among treatments. However, ether extract and NDF intakes increased, whereas starch intake decreased linearly as BP ingredients increasingly replaced HE feed ingredients. Eating time was not affected by dietary treatment, but ruminating and total chewing time tended to increase with increasing amounts of BP. Replacing HE with BP ingredients did not affect rumen pH. An increased proportion of BP ingredients in the diet linearly decreased propionate, isobutyrate, isovalerate and valerate concentrations in the rumen and increased acetate concentration and the acetate to propionate ratio. Replacing HE with BP ingredients did not affect milk yield. The yield of 3.5% FCM (39.12, 40.14 and 41.33 kg/d for BP26, BP60 and BP95, respectively) and fat content (2.95, 2.99 and 3.13 % for BP26, BP60 and BP95, respectively) linearly increased. Substituting BP ingredients for HE feed ingredients increased unsaturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, stearic acid, oleic acid and preformed fatty acids but decreased saturated fatty acids, palmitic acid, de novo and mixed fatty acids. Replacing HE with BP feed ingredients increased human-edible efficiency (HeFCE) for crude protein (1.06, 1.66 and 4.14 kg/kg edible for BP26, BP60 and BP95, respectively) and for energy (2.27, 3.62 and 9.22 MJ/MJ edible for BP26, BP60 and BP95, respectively) and also net food production (NFP) for crude protein (0.064, 0.52, and 1.00 kg/d for BP26, BP60, and BP95, respectively) and energy (62.8, 83.0 and 104.7 MJ/d for BP26, BP60 and BP95, respectively). Feeding byproduct-based concentrates instead of human-edible feed ingredients increase human-edible feed conversion efficiency (HeFCE), net food production (NFP) and improved the performance of high-producing Holstein cows.

Effects of substitution of beet pulp for barley or corn in the diet of high-producing dairy cows on feeding behavior, performance, and ruminal fermentation

This study investigated the effects of substituting beet pulp (BP) for different grains (barley or corn) in the diet of high-producing dairy cows on intake, feeding behavior, nutrient digestibility, ruminal fermentation, milk production, and feed conversion efficiency. Eight second-parity Holstein cows (62 ± 2 d in milk; milk yield = 54 ± 1.2 kg/d; body weight = 624 ± 26; all mean ± SE) were used in a replicated 4 × 4 Latin square design during 4 periods of 21 d. Cows were randomly assigned to 1 of 4 treatments that were a 2 × 2 factorial arrangement of 2 grain sources (corn or barley) and 2 levels of BP inclusion [5 or 15% of dry matter (DM)] in the diet: (1) barley-based diet with BP at 5% of dietary DM; (2) barley-based diet with BP at 15% of dietary DM; (3) corn-based diet with BP at 5% of dietary DM; and (4) corn-based diet with BP at 15% of dietary DM. The increasing amount of BP in the diet was at the expense of decreasing an equal proportion of grain (barley or corn). All diets were high in concentrates (65% of diet DM) and formulated to have similar concentrations of energy and protein. The portion of feedstuffs that is potentially able to be consumed by humans is known as human edible. Accordingly, human-edible protein (HEP) and human-edible energy (HEE) inputs were calculated according to the recommended potential human-edible fraction of each dietary ingredient, and HEP and HEE outputs were determined as the amount of gross energy and true protein in the milk. Feed conversion efficiency (FCE) for HEP and HEE were expressed as output per input of each variable, whereas FCE for the production of fat-corrected milk (FCM) and energy-corrected milk (ECM) were expressed as the amount of each variable per DM intake. Results showed that substituting BP for grain did not affect DM intake, crude protein intake, or nutrient digestibility, whereas starch intake (5.70 vs. 7.43 kg/d for the low-BP vs. high-BP diets, respectively), HEP (2.34 and 1.92 kg/d), and HEE (186 and 147 MJ of gross energy/d) decreased. Treatments did not affect sorting and chewing activities, but increasing BP in the diet increased ruminal pH at 4 h after feeding (6.20 vs. 6.39) and milk fat content (2.92 vs. 3.15%). Similarly, FCE for ECM production (1.44 vs. 1.54) as well as FCE for HEE (0.653 vs. 0.851) and HEP (0.629 vs. 0.702) were greater in high-BP diets compared with low-BP diets. The interaction of BP and grain sources significantly affected FCE for ECM production, where improvements were more evident when BP was substituted for barley than for corn. The improvement in FCE for HEE was greater when BP was substituted for barley (0.236) rather than corn (0.161). In conclusion, the substitution of BP for barley or corn grains in high-concentrate diets of high-producing cows decreased starch intake, increased ruminal pH at 4 h after feeding, and improved FCE for FCM production. Substitution for barley, rather than for corn, promoted greater FCE for ECM production and HEE.

Inline Reticulorumen pH as an Indicator of Cows Reproduction and Health Status

Our study hypothesis is that the interline registered pH of the cow reticulum can be used as an indicator of health and reproductive status. The main objective of this study was to examine the relationship of pH, using the indicators of the automatic milking system (AMS), with some parameters of cow blood components. The following four main groups were used to classify cow health status: 15-30 d postpartum, 1-34 d after insemination, 35 d after insemination (not pregnant), and 35 d (pregnant). Using the reticulum pH assay, the animals were categorized as pH < 6.22 (5.3% of cows), pH 6.22-6.42 (42.1% of cows), pH 2.6-6.62 (21.1% of cows), and pH > 6.62 (10.5% of cows). Using milking robots, milk yield, fat protein, lactose level, somatic cell count, and electron conductivity were registered. Other parameters assessed included the temperature and pH of the contents of reticulorumens. Assessment of the aforementioned parameters was done using specific smaX-tec boluses. Blood gas parameters were assessed using a blood gas analyzer (EPOC (Siemens Healthcare GmbH, Erlangen, Germany). The study findings indicated that pregnant cows have a higher pH during insemination than that of non-pregnant ones. It was also noted that cows with a low fat/protein ratio, lactose level, and high SCC had low reticulorumen pH. They also had the lowest blood pH. It was also noted that, with the increase of reticulorumen pH, there was an increased level of blood potassium, a high hematocrit, and low sodium and carbon dioxide saturation.

Effects of two new formulas of dietary buffers with a high buffering capacity containing Na or K on performance and metabolism of mid-lactation dairy cows

The present study was conducted to evaluate the effect of two new formulas of dietary buffers on intake, total tract digestibility, rumen pH, blood metabolites, and milk production of mid-lactation dairy cows. Nine multiparous cows (594 ± 46 kg BW; mean ± SD) averaging 120 ± 28 days in milk and producing 46.6 ± 3.4 kg/d were randomly assigned to a triplicate 3 × 3 Latin square. During each 21-d period, cows were offered one of three total mixed rations that varied in dietary buffer. The three types of dietary buffer were 1) 11.2 g/kg of dietary dry matter (DM) sodium bicarbonate (SB; control), 2) 8.7 g/kg of dietary DM high buffering capacity formula contained Na (HBNa), and 3) 7.4 g/kg of dietary DM high buffering capacity formula contained K (HBK). Each period was comprised of 14 d of dietary adaptation followed by 7 d of sampling. Measured buffering capacity was 102, 150 and 137 percent of NaHCO₃ for SB, HBNa and HBK, respectively. The amount of Na and K were 270 and 0, 310 and 0, and 250 and 60 g/kg for SB, HBNa, and HBK, respectively. Dry matter intake (DMI) tended (P = 0.06) to be lower with HBK (20.6 kg/d) than SB (21.0 kg/d) and HBNa (21.2 kg/d). No treatment effects were observed on rumen pH (averaged 5.88) and DM digestibility in the total digestive tract (averaged 79.4%). Yields of actual milk (38.1 kg/d) and 3.5% fat corrected milk (31.6 kg/d) were not affected by treatments, whereas yields of solid corrected milk (P = 0.07) and milk fat (P = 0.10) tended to be greater with HBK than SB and HBNa. Milk fat concentration in cows fed HBK was greater than in cows fed other treatments (32.5 vs. 29.5 and 29.6 g/kg; P = 0.04). Concentration of milk protein (32.2 vs. 30.6 g/kg) and lactose (46.8 vs. 44.4 g/kg) also were greater in cows fed HBK than those fed SB (P = 0.02). Efficiency of milk production was greater in cows fed HBK than SB (1.86 vs. 1.80; P = 0.01), whereas efficiency of solid corrected milk production was greater in HBK than SB and HBNa (1.64 vs. 1.51 and 151; P = 0.02). Blood concentration of Ca was higher with HBK compared with SB and HBNa (10.4 vs. 9.7 and 9.9 mg/dL, respectively; P = 0.01). These results indicated that under the current experimental condition, supplementation of dairy cow diet with a high buffering capacity buffer containing 60 g/kg K decreased DMI and improved milk composition and milk efficiency of mid-lactation dairy cows.

Implications of low fiber levels in finishing lambs on performance, health, rumen, and carcass parameters

The objective of this study was to evaluate the effects of different levels of NDF in high-concentrate diets on performance and aspects ruminal, blood, and carcass parameters of finishing lambs. Twenty-four lambs, with initial BW of 24 ± 3 kg, were randomly divided into individual pens, in a completely randomized design, comprising three treatments with eight repetitions each. The treatments consisted of dietary levels of 15%, 20%, and 25% of NDF, based on DM. The diets were composed of corn, soybean meal, minerals, and corn silage and were offered twice a day, with daily control of what was offered and refused, to determine dry matter intake (DMI). The animals were weighed weekly and slaughtered after 50 days of confinement. Performance evaluations, blood parameters, carcass, and ruminal parameters were evaluated. Lambs fed with lower dietary fiber had better carcass yield (P < 0.005). Blood count, blood biochemical parameters, rumen short-chain fatty acid production and protozoan population were not affected by the dietary NDF level. It was concluded that in high-concentrate diets with 15% NDF resulting in better weight gain of the animals in the confinement, good carcass yields without the animal having altered health and ruminal parameters.