Effect Of Dietary Concentrate Level, Forage To Concentrate Ratio And Forage Particle Size On Growth Performance And Behavior Of Holstein Male Calves

In China, the beef cattle industry is spreading and with high frequency and dairy cattle male calves are being introduced in beef production to full fill the requirement of the beef industry. To obtain maximum production and higher profitability from these kinds of animals high concentrate feed is practiced along with crop residues. The concentrate level, inclusion level and forage particle size is frequently changed by farmer which may not only affect the growth but also normal feeding behavior. However, the knowledge of introducing crop residues at different level and concentrate level on dairy male calves is limited. Therefore, a study was planned to evaluate the effect of concentrate level, forage concentration (F:C) and forage particle length (FPL) on intake, growth, sorting, and feeding behavior, of growing Holstein bulls.Three major experiments were conducted to obtain the result and each experiment was carried out for three months. Twenty-eight weaned calve were used in with the factors concentrate level, forage concentration (low,50% and high,65%), and FPL In first experiment treatments were four concentrate levels,1-1.5kg (LC),1.5-2kg (MC),2-2.5kg (HC), and 2.5-3kg (H+C) and forage was fed ad libitum. In the 2nd and 3rd experiment treatments were Full length (FL) with low F:C (50:50), FL with high F:C(65:35), Short length (SL) with low F:C (50:50), and SL with high F:C (65:35), respectively.In first experiment corn stover (CS) was fed to Chinese Holstein bulls (227±6.8 SD kg) as a sole source of fiber with different levels of concentrate, nutrient intake, digestibility, ruminal metabolites and performance of Chinese Holstein bulls were determined. Dietary concentrate level, month and their interaction had the effect on dry matter intake (DMI), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) intake. The highest intake value of DMI, CP, ADF and NDF was found on the third month (P<0.05). On the third month, increasing the concentrate level had increased ADF, and NDF intake in LC and MC and decreased in HC and H+C (P<0.05). An increasing trend was observed for organic matter (OM) intake (P<0.5) and CS DMI as dietary concentrate level increased from LC to HC. Similarly, rumen NH3-N, acetate, butyrate, and valerate increased with increasing concentrate level from LC to HC while in the case of propionate increasing the concentrate enhanced the amount of propionate and highest value of propionate was observed at H+C level (P<0.05). Results of nutrient digestibility indicated that OM (P<0.05), and CP (P<0.05) digestibility increased with increasing concentrate level. In the case of NDF, and ADF digestibility, highest values were found at HC level of concentrate. Body weight gain (P<0.05), average daily gain and body measurements (P<0.05), height (P<0.05), chest (P<0.05), abdomen (P<0.05) and waist (P<0.05) highest values were increased by increasing the concentrate level and highest value were found at H+C level of concentrate. In the case of preferential intake, animal tried to finish the concentrate in one meal and concentrate eating time was increased by increasing the concentrate level (P<0.5) while concentrate eating time per kg concentrate decrease with increasing concentrate (P<0.5). Corn stovers eating time was decreased by increasing the concentrate level from LC to HC level of concentrate and but interestingly increase of CS eating time was observed by increasing concentrate level from HC to H+C (P<0.5). Similar trends was found for CS eating time per kg CS DMI and chewing time per kg CS DMI by increasing the concentrate level (P<0.5) while chewing time was increased by increasing the concentrate level from LC to HC (P<0.5) and decrease of chewing time was observed from HC to H+C level of concentrate (P<0.5). The analysis of the diurnal pattern of concentrate intake time, silage intake time, chewing time, laying and abnormal behavior showed treatment by hour interaction (P<0.05). The highest time consumed to take concentrate was observed in H+C (P<0.05). While, the lowest time consumed to take concentrate was observed in LC (P<0.05). Highest time consumption for silage was observed for LC on 16:00th hour (P<0.05) of the day. After morning feed delivery, H+C fed animals showed highest chewing activity (P<0.05). Similarly, chewing for H+C activity was at a peak at 4:00th hour and 18:00th hour of the day (P<0.05). Animal’s which were on LC treatment showed higher laying behavior during 18:00th and 24:00th hour of the day (P<0.05). A similar trend was observed during 1st to the 6th hour of the day. Abnormal behavior was highest on 09:00th and 16:00th hour of the day (P<0.05). At 09:00th hour of the day H+C showed abnormal behavior at their highest extent (P<0.05). Low concentrate fed animals showed higher abnormal behavior as compared to H+C at 16:00th hour of the day (P<0.05).Study to check the effect of forage inclusion level at full forage particle length revealed CP intake was not affected by F:C (p>0.05). Organic matter, NDF and ADF were affected by F:C (p<0.05). Increasing the F:C enhances the intake of OM, NDF and ADF (p<0.05). Blood glucose, blood urea nitrogen (BUN), total protein (TP), testosterone (T), and thyroxin (T3) were not affected by F:C (p>0.05). Cholesterol and leptin (LP) level in the blood was increased by increasing the F:C (p<0.05). Growth hormone level was affected by F:C, it was increased by increasing the F:C (p<0.05). Nutrient digestibility was not affected by F:C, Results of sorting show that intensity of sorting for short and fine particle, and against long particle increased at higher F:C. Eating time per kg DMI increased by increasing F:C level in FL. Increasing the F:C increased the eating time (P<0.05) and highest eating time was observed for high F:C and peak eating activity was found at lstand 2ndhour after feed delivery (P<0.05). Chewing time was affected by the hours (P<0.05). Increasing F:C increased chewing time per kg DMI. High F:C decreased the laying time (P< 0.05) in FL (P< 0.05). Highest chewing and lying activity was observed during 4thto the 8thhour after feed delivery (P<0.05). Stereotype behavior was affected by treatment and hour and low F:C diet showed a higher stereotype behavior. Increasing F:C reduced the overall stereotype behavior (P< 0.05). Continuous stereotype behavior was observed in both treatments, from lsthour to 9thhour after feed delivery at low F:C diet and from 2ndhour to the 9thhour after feed delivery at high F:C diet. Social behavior was altered by hours (P<0.05) and social activity was highest during 1st to 3rdand 9thhour after feed delivery.Investigation of forage inclusion level at short forage particle size revealed that CP intake was not affected by F:C (p>0.05). Organic matter, NDF and ADF were affected F:C. Organic matter intake was increased by increasing the F:C (p< 0.05). Increasing the F:C enhance the intake of NDF and ADF (p <0.05)intake(p<0.05), respectively. Blood glucose, BUN, TP, T, and T were not affected by F:C (p>0.05). Cholesterol and LP level in the blood was increased by increasing the F:C (p<0.05). Growth hormone level was affected by F:C, it was increased by increasing the F:C (p<0.05). Nutrient digestibility was not affected by F:C. Increasing F:C enhanced sorting for short and fine particle and sorting against long particle (P<0.05). Eating time was affected by both dietary treatment and hour (P<0.05) and Increasing the F:C increased the overall eating time in SL (P<0.05). Eating time per kg DMI increased by increasing F:C level in SL treatment. Chewing time was influenced by hours (P<0.05) and increasing trend was observed at high F:C level from 1st to hours after feeding while at low F:C level increasing trend was observed from 2nd to 7th hour after feed delivery. Increasing F:C increased chewing time per kg DMI. High F:C decreased the laying time (P< 0.05) in SL treatments (P< 0.05). There was an interaction for laying time and highest lying time was observed at 4th and 7 hour after feed delivery in high F:C animals (P<0.05). Animals which were on low F:C showed a higher stereotype behavior (P<0.05). Social activity was highest from 1st to 2nd and at the 9th hour after feed delivery (P<0.05).Increasing the concentrate level enhance the growth. Increasing the concentrate in the diet alters animal behavior, silage intake time, enhance rumination activity and increase abnormal behavior that could compromise animal welfare. Increase in forage inclusion in the diet of the weaned calves influence the nutrient intake. Increasing the forage concentration reduced animal’s abnormal behavior.