Kilogram Of Metabolic Body Weight Research Articles

Intake, digestibility, energy and nitrogen utilisation, and enteric methane emission in Holstein and Girolando-F1 cows during the transition period

ABSTRACT This study aimed to evaluate intake, energy and nitrogen balance as well as methane emission in Holstein and ½ Holstein ½ Gyr (Girolando-F1) cows during the transition period. Twenty-four cows (12 Holstein and 12 Girolando-F1) were used to evaluate feed intake, apparent digestibility, heat production and methane emission, carried out in two periods: from 28 to 19 days pre-calving and from 15 to 23 days post-calving. A completely randomised design was used and data were analysed by ANOVA within periods (pre- and post-calving) considering the main effect of genetic groups. Girolando-F1cows presented greater body condition score (BCS) compared with Holstein. During pre-calving, there were no differences between genetic groups, except for highest heat production per kilogram of metabolic body weight for Holstein cows. After calving, Holstein cows had greater intake of DM, nitrogen, NDF per kg of BW and produced more heat per kg of metabolic body weight. Holstein cows yielded more milk and fat-corrected milk (FCM4%) compared with Girolando-F1 cows. Holstein cows presented higher methane emission per unit of BW and of metabolic weight. Emissions of enteric methane per kilogram of milk and per kilogram of FCM4% tended to be lower for Holstein compared with Girolando-F1 cows. Nitrogen and energy retention were similar for both Holstein and Girolando-F1 at pre- and post-calving. Despite differences in BCS, DMI, and milk yield, Girolando-F1 and Holstein cows present overall similar energy efficiency, albeit Holstein cows tended to present less methane emission per kg of eligible product (milk).

Low dietary protein resilience is an indicator of the relative protein efficiency of individual dairy cows

Our objectives were to determine (1) the sources of variation in cow responses to dietary protein reduction, and (2) the association of low dietary protein resilience (LPR) with protein efficiency. Lactating Holstein cows in peak lactation (n = 166; 92 primiparous, 77 multiparous) with initial milk yield 41 ± 9.8 kg/d were fed high-protein (HP) or low-protein (LP) diets in 4-wk periods in a crossover design with half the cows fed LP first and half fed HP first. The study was repeated for 69 of these cows (42 primiparous, 27 multiparous) in late lactation. Low-protein diets were 14% crude protein (CP) in peak lactation and 13% CP in late lactation and were formulated to contain adequate rumen-degradable protein to maintain rumen function but inadequate rumen-undegradable protein for cows with average production in this study to maintain their production. High-protein diets were 18% CP in peak lactation and 16% CP in late lactation and contained extra expeller soybean meal to meet metabolizable protein requirements. Protein efficiency was defined as the protein captured in milk or in both milk and body tissues per unit of consumed protein. Low dietary protein resilience was calculated for each cow in peak and late lactation based on actual intake, production, and body weight measures. The ability of a cow to maintain total protein captured in milk and body gain when fed less protein varied considerably and the variation was mostly explained by a cow's captured protein per kilogram of metabolic body weight when fed HP, her parity, treatment sequence, and experiment. Protein efficiency was moderately repeatable across diets within lactation stage. Milk urea nitrogen was not associated with protein efficiency in individual cows within a diet and lactation stage. Cows with greater dietary protein resiliency (higher LPR) had similar protein efficiency on the HP diet as cows with lower LPR, but higher protein efficiency on the LP diet. In conclusion, cows generally maintained their protein efficiency rankings when switching diets between sufficient or insufficient protein; however, some high-producing cows are better able to maintain high production when fed less protein. We define this ability as LPR and suggest it might be useful for identifying cows that use protein more efficiently to enhance dairy sustainability.

Effects of preweaning nutrient intake in the developing mammary parenchymal tissue

Historically, mammary gland growth has been considered isometric the first 2 mo of life and then allometric until peripuberty. However, recent work indicated that the mammary gland might be responsive to nutrient intake preweaning. The objectives of this study were to describe the effects of nutrient intake preweaning on mammary gland development and to investigate cell specific proliferation during this phase of development. Twelve dairy heifer calves were fed either a fixed amount of milk replacer (MR; control, n = 6) or an amount of MR adjusted for BW (enhanced, n = 6). Control calves received a constant amount of a 28% crude protein, 15% fat milk MR per day that was equivalent to 2.8 Mcal of metabolizable energy intake per day; enhanced calves received 0.3 Mcal of metabolizable energy intake per kilogram of metabolic body weight (from 4.2 to 8.4 Mcal of metabolizable energy intake per day). All calves had constant access to water and a 22% crude protein commercial calf starter. Calves were killed at 54 ± 2 d. Control calves consumed 32.6 ± 2.4 kg of MR and 6.7 ± 0.5 kg of calf starter per calf, whereas the enhanced calves consumed 69.5 ± 2.4 kg of MR and 1.9 ± 0.5 kg of calf starter per calf over the 54-d period. Further, to evaluate putative stem cell proliferation, BrdU (5-bromo-2'-deoxyuridine; 5 mg/kg) was injected intramuscularly once per day between 12 to 15 d and again once per day between 24 to 27 d of life. Initial and final body weight for the control and enhanced treatments were 39.2, 61.0, 39.7, and 83.2 kg, respectively. At euthanasia, weights of liver, kidneys, pancreas, whole skinned mammary gland, and mammary parenchyma were measured. The growth rate of each organ was calculated using the concept of allometry as the difference in the change in organ weight as a percentage of body weight. The mammary glands of calves fed the enhanced diet were significantly heavier at euthanasia; when mammary parenchymal weight was analyzed, enhanced calves had 5.9 times greater mammary parenchymal mass, indicating the mammary gland was responsive to nutrient intake before weaning. Allometric growth of the mammary gland was initiated preweaning in the calves fed the enhanced treatment. Further characterization of mammary cells that retained BrdU label revealed no significant differences among the tissue slices analyzed between treatments; however, as calves fed the enhanced diet had more mammary parenchymal mass, if the number of label-retaining cells per counted slide were similar between treatments then the enhanced calves had a larger total population of putative mammary stem cells present in the mammary gland.

Effects of lactic acid bacteria silage inoculation on methane emission and productivity of Holstein Friesian dairy cattle

Inoculants of lactic acid bacteria (LAB) are used to improve silage quality and prevent spoilage via increased production of lactic acid and other organic acids and a rapid decline in silage pH. The addition of LAB inoculants to silage has been associated with increases in silage digestibility, dry matter intake (DMI), and milk yield. Given the potential change in silage and rumen fermentation conditions accompanying these silage additives, the aim of this study was to investigate the effect of LAB silage inoculants on DMI, digestibility, milk yield, milk composition, and methane (CH4) production from dairy cows in vivo. Eight mid-lactation Holstein-Friesian dairy cows were grouped into 2 blocks of 4 cows (multiparous and primiparous) and used in a 4×4 double Latin square design with 21-d periods. Methane emissions were measured by indirect calorimetry. Treatments were grass silage (mainly ryegrass) with no inoculant (GS), with a long-term inoculant (applied at harvest; GS+L), with a short-term inoculant (applied 16h before feeding; GS+S), or with both long and short-term inoculants (GS+L+S). All diets consisted of grass silage and concentrate (75:25 on a dry matter basis). The long-term inoculant consisted of a 10:20:70 mixture of Lactobacillus plantarum, Lactococcus lactis, and Lactobacillus buchneri, and the short-term inoculant was a preparation of Lc. lactis. Dry matter intake was not affected by long-term or short-term silage inoculation, nor was dietary neutral detergent fiber or fat digestibility, or N or energy balance. Milk composition (except milk urea) and fat and protein-corrected milk yield were not affected by long- or short-term silage inoculation, nor was milk microbial count. However, milk yield tended to be greater with long-term silage inoculation. Methane expressed in units of grams per day, grams per kilogram of DMI, grams per kilogram of milk, or grams per kilogram of fat and protein-corrected milk yield was not affected by long- or short-term silage inoculation. However, CH4 expressed in units of kilojoules per kilogram of metabolic body weight per day tended to be greater with long-term silage inoculation. Results of this study indicate minimal responses in animal performance to both long- and short-term inoculation of grass silage with LAB. Strain and dose differences as well as different basal silages and ensiling conditions are likely responsible for the lack of significant effects observed here, although positive effects have been observed in other studies.

Enteric Methane Emission, Energetic Efficiency and Energy Requirements for the Maintenance of Beef Cattle in the Tropics

This study was conducted to determine the energy balance of beef cattle by indirect animal calorimetry utilizing a ventilated head box respiration system. Fifteen native Thai bulls were randomly allocated to one of three dietary metabolizable energy intake (MEI) levels (1.1 × maintenance, 1.5 × maintenance and 1.9 × maintenance) in a completely randomized design for a 116 day feeding trial. Animals were allocated to individual metabolic cages for the determination of digestibility and energy balance. Heat production was determined from oxygen consumption, carbon dioxide and methane production. The results showed that dry matter, organic matter and crude protein intake were increased (P 0.05) by MEI levels. The energy loss in feces and urine (% of gross energy intake) were not different (P > 0.05); however, enteric methane conversion rate (% of methane energy loss per gross energy intake) and heat energy production loss (% gross energy intake) were linearly decreased (P < 0.01) with increasing MEI levels. Methane conversion rates ranged from 8.4 to 10.0% and appeared to have been underestimated by the Intergovernmental Panel on Climate Change 6.5% default values set for cattle fed low quality crop residues and by-products. The estimate of metabolizable energy requirements for maintenance was measured using linear regression analysis derived for native Thai cattle was 520 kilojoules per kilogram of metabolic body weight per day. Increased dietary intake levels reduced enteric methane emissions in beef cattle fed on tropical feedstuffs. The results of the present study indicated that greater dietary intake feeding strategy in cattle fed above the maintenance level resulted in improved energetic efficiency utilization, and thus improved energy retention because of the reduction of enteric methane energy emission and heat production. Discipline: Animal industry Additional key words: cattle, energy requirements, enteric methane, tropical This paper reports results obtained in the international project on “Establishment of feeding standard of beef cattle and feedstuff database in Indochina.” The Japan International Research Center for Agricultural Sciences, Department of Livestock Development, Ministry of Agriculture and Cooperatives, Thailand, and Khon Kaen University took responsibility for all subjects picked up in the project, implemented main subjects jointly and managed the project. Since it is essential to construct a regional research cooperation network for the efficient achievement of the targets, other research organizations such as Mahasarakham University, Ubon Ratchatanee University, Rajamangala University of Technology-Isan, Suranaree University of Technology, Chiang Mai University, Maejo University, Prince of Songkla University, National University of Laos, Lao PDR, and Royal University of Agriculture, Cambodia were also involved in the project. The project was implemented during the five-year period from 2006 to March 2011. Present address: 4 Division of Animal Sccience, Faculty of Technology, Mahasarakham University (Mahasarakham 44150, Thailand) 5 NARO Institute of Livestock and Grassland Science (Tsukuba, Ibaraki 305-0901, Japan) *Corresponding author: e-mail: kritapon@kku.ac.th Received 2 December 2014; accepted 31 March 2015.

Effects of feeding level on methane emissions and energy utilization of Brahman cattle in the tropics

The release of methane from ruminant livestock is a problem not only because it contributes to greenhouse gas emissions but also because it affects feed energy utilization and animal production efficiency. The objective of this experiment was to determine the effects of feeding level on methane emission and energy utilization of Brahman cattle (Bos indicus). Sixteen 2-year-old Brahman steers were housed in individual pens for a 70-day feeding experiment. Dietary treatments were applied in a randomized complete block design with four replications and four feeding levels (M, 1.4×M, 1.8×M, and ad libitum; where M represents a metabolizable energy requirement for maintenance. The animals were placed in a metabolic cage equipped with a ventilated head box system to determine the total collection digestibility and energy balance. Energy partitioning in response to feeding level significantly linearly increased. Although the total tract digestibility of dry matter, organic matter, crude protein, and neutral detergent fiber were affected slightly depressed, total feed intake, nutrient intake, and energy intake increased dramatically as feeding levels increased. Methane emission rate decreased (from 11.5 to 7.3%) with increasing feeding level, yet these values are much higher than the IPCC recommended value (6.5%) for calculation of national inventory of enteric methane emissions. A daily metabolizable energy requirement for maintenance was estimated at 435 kilojoules of metabolizable energy per kilogram of metabolic body weight, and the estimated efficiency of the utilization of metabolizable energy for growth was 0.54. Our study found that increasing feeding level increased average daily gain of Brahman cattle and the observed increased energetic efficiency was attributed to reduced energy output in urine, methane and heat production.

The energy expenditure of 2 Holstein cow strains in an organic grazing system

Until recently, measurements of energy expenditure (EE; herein defined as heat production) in respiration chambers did not account for the extra energy requirements of grazing dairy cows on pasture. As energy is first limiting in most pasture-based milk production systems, its efficient use is important. Therefore, the aim of the present study was to compare EE, which can be affected by differences in body weight (BW), body composition, grazing behavior, physical activity, and milk production level, in 2 Holstein cow strains. Twelve Swiss Holstein-Friesian (HCH; 616kg of BW) and 12 New Zealand Holstein-Friesian (HNZ; 570kg of BW) cows in the third stage of lactation were paired according to their stage of lactation and kept in a rotational, full-time grazing system without concentrate supplementation. After adaption, the daily milk yield, grass intake using the alkane double-indicator technique, nutrient digestibility, physical activity, and grazing behavior recorded by an automatic jaw movement recorder were investigated over 7d. Using the 13C bicarbonate dilution technique in combination with an automatic blood sampling system, EE based on measured carbon dioxide production was determined in 1 cow pair per day between 0800 to 1400h. The HCH were heavier and had a lower body condition score compared with HNZ, but the difference in BW was smaller compared with former studies. Milk production, grass intake, and nutrient digestibility did not differ between the 2 cow strains, but HCH grazed for a longer time during the 6-h measurement period and performed more grazing mastication compared with the HNZ. No difference was found between the 2 cow strains with regard to EE (291±15.6kJ) per kilogram of metabolic BW, mainly due to a high between-animal variation in EE. As efficiency and energy use are important in sustainable, pasture-based, organic milk production systems, the determining factors for EE, such as methodology, genetics, physical activity, grazing behavior, and pasture quality, should be investigated and quantified in more detail in future studies.

Diet Digestibility, Rate of Passage, and Eating and Rumination Behavior of Jersey and Holstein Cows

Diet digestibility and rate of passage, eating and rumination behavior, dry matter intake (DMI), and lactation performance were compared in 6 Jersey and 6 Holstein multiparous cows. Cows were fed gestation diets according to body weight (BW) beginning 7 wk before expected calving and ad libitum amounts of a lactation diet postpartum. Diet digestibility and rate of passage were measured in 5-d periods at wk 5 prepartum and wk 6 and 14 of lactation. Eating and ruminating behavior was measured over 5-d periods at wk 5 and 2 prepartum and wk 2, 6, 10, and 14 of lactation. Milk yield and DMI were higher in Holsteins, but milk energy output per kilogram of metabolic BW (BW0.75) and intake capacity (DMI/kg of BW) did not differ between breeds. Holsteins spent longer ruminating per day compared with Jerseys, but daily eating time did not differ between breeds. Jerseys spent more time eating and ruminating per unit of ingested feed. The duration and number of meals consumed did not differ between breeds, but the meals consumed by Jerseys were distributed more evenly throughout each 24-h period, providing a more regular supply of feed to the rumen. Feed passed through the digestive tract more quickly in Jerseys compared with Holsteins, suggesting particle breakdown and rumen outflow were faster in Jerseys, but this may also reflect the relative size of their digestive tract. Neutral detergent fiber digestibility was greater in Jerseys, despite the shorter rumen retention time, but digestibility of dry matter, organic matter, starch, and N did not differ between breeds. Utilization of digested N for tissue retention was higher at wk 5 prepartum and lower at wk 14 of lactation in Jerseys. In contrast to numerous published studies, intake capacity of Jerseys was not higher than that of Holsteins, but in the present study, cows were selected on the basis of equal expected milk energy yield per kilogram of metabolic BW. Digestibility of neutral detergent fiber and rate of digesta passage were higher in Jerseys, probably as a consequence of increased mastication per unit of feed consumed in Jerseys and their smaller size.

Effect of Feed Restriction Using Self-Restricting Diets on Subsequent Performance of Broiler Breeder Females

Two qualitative feed restriction methods were compared in terms of feed intake regulation, pullet growth, and subsequent reproductive performance in broiler breeder hens. Three-week-old female chicks were physically feed-restricted, provided ad libitum access to diets supplemented with or without propionic acid (30 g/kg), or fed a diet composed of barley as the main amino acid source. The incorporation of propionic acid alone to a low-energy diet significantly inhibited voluntary feed intake. However, after 10 wk of ad libitum consumption, dietary propionate supplementation proved less effective in controlling pullet growth than conventional feed restriction. The barley diet was more effective than physical feed restriction in limiting body weight gain. No negative side effects were observed in the feed-restricted birds, except for a slight increase in the coefficient of variation in BW during the growing period. No significant differences in egg production between the self-restricted and physically restricted control birds were measured during the study. Egg weights from birds fed the barley diet were lowest throughout the experimental period and were accompanied by lower ME intake per kilogram of metabolic body weight.

Protein Requirement of White-Tailed Deer Fawns

Eight hand-reared white-tailed deer (Odocoileus virginianus) fawns were randomly paired and pairs were randomly assigned to 1 of 4 isocaloric diets containing 11, 15, 20, and 25 percent crude protein (dry matter basis) to study their protein requirement. Thirty-two complete digestibility, nitro- gen balance, and energy balance trials were carried out. Partition of dietary energy was not signifi- cantly affected by protein level in the diet, except that proportion of energy lost in urine, presumably ketones, increased significantly (P < 0.05) with increasing dietary crude protein. Apparent digestibility of protein increased significantly up to 20 percent ration crude protein, but most of this difference was attributable to decreasing proportion of metabolic nitrogen (0.37 g/100 g diet dry matter) in feces; proportion of ingested nitrogen lost in urine increased with increasing nitrogen intake. The fawn's re- quirement for maximum growth (body retention of dietary protein), estimated by regression analysis, was 19 g digestible crude protein per kilogram of metabolic body weight (W075) daily. J. WILDL. MANAGE. 39(3):582-589 White-tailed deer, an aesthetically and economically valuable resource, are increas- ingly threatened by the effects of urban- ization in many areas. Their survival in optimum quantity and quality will depend largely on intensive management based on biologically sound principles. Deer man- agers will need information on the nutri- tional requirements of different age classes of deer throughout the year, and on the value of natural foods in meeting these re- quirements. Fawns probably are the age class most vulnerable to undernutrition during the winter. Certainly the food consumed dur- ing the preceding fall contributes greatly to winter survival. Thompson et al. (1973: 307) reported that the metabolizable energy required for maintenance of fawns is higher (38 percent, our calculation) during pe- riods of weight gain than in winter. They also found that the component of growth described by deposition of body protein may continue despite body weight loss and negative energy balance during the winter. Although energy generally is the most crit- ical factor in deer nutrition, the work of Murphy and Coates (1966) suggested that low protein content of foods may account for low productivity and suboptimum phys- ical development as in most other species.

Efficiency of Energy Utilization by Young Cattle Ingesting Diets of Hay, Silage, and Hay Supplemented with Lactic Acid1,2

Summary The purposes of this study were to determine whether the energetic efficiency of the dry matter of silage is different from that of hay harvested at the same time from the same source of forage, and whether the relative concentrations of the fatty acids in ruminal ingesta are associated with the utilization of energy. To pursue these objectives, the energy losses by growing cattle ingesting the following diets at the same level of dry matter per unit of metabolic size, were partitioned: (a) hay, (b) silage, and (c) hay supplemented by intraruminal infusions of lactic acid. These studies revealed no difference among treatments in the size of the energy loss in feces (i.e., there was no difference in the digestibility of energy), urine, or in methane as estimated from digestible carbohydrates. However, the mean outputs of metabolic heat estimated from oxygen consumption and urinary nitrogen excretion were 110.3, 93.5, and 93.4 kcal per 24 hr per kilogram of metabolic-body weight of steers ingesting hay, silage, and hay supplemented with lactic acid, respectively. As a consequence, the following percentages of the metabolizable energy were retained by the steers ingesting the three diets: hay, 18.0; silage, 33.4; and hay supplemented with lactic acid, 28.9. Although these differences were not mathematically significant, in only one instance was the retention of energy even slightly higher for the hay diet than it was for the two other diets. The molar proportions of the following fatty acids as percentages of the total acids in the rumen ingesta of animals fed hay, silage, and hay supplemented with lactic acid, respectively, were: acetic acid, 69.5, 58.3, and 57.4; propionic acid, 18.5, 20.7, and 28.7; butyric acid, 9.8, 15.4, and 11.0; and higher acids, 2.2, 5.6, and 2.8. Thus, the diet of hay alone was associated with a higher proportion of acetic acid and lower concentrations of propionic and butyric acids in ruminal ingesta than were the diets of silage or of hay supplemented with lactic acid. These observations indicate that the energetic efficiency of body gain in young cattle ingesting forage diets is favored by diets resulting in a high proportion of propionic and butyric acids relative to acetic acid in the rumen.